Crop Coefficients

Close management of irrigation could have considerable impacts on water resources, especially for cropping systems dominated by corn. The experiment was carried out to compare the influence of porous capsule irrigation (PCI), surface drip irrigation (DI), and subsurface drip irrigation (SDI) systems, with or without mulching, on actual evapotranspiration (ETc act), crop coefficients (K c single and K c dual), biomass yield, and water use efficiency (WUE) of corn in a semiarid region of Iran. The experiment was arranged in a split-plot design with the three irrigation systems assigned to the main plots and two mulching (with or without foil type) treatments (M 1 and M 2) assigned to the sub-plots. The corn ETc act varied significantly (P < 0.05) with the different irrigation systems, being (mm) 389.8 for PCI, 377.0 for DI, and 372.8 for SDI. The highest K c average and K cb (0.82 and 1.22) and the lowest K e (0.12) were observed under the PCI system. The dry and wet biological biomass yields were highest (29.98 and 107 t/ha) under the PCI + M 1 treatment, and the lowest (23.19 and 58.54 t/ha, respectively) were under the DI + M 2 treatment. The highest WUE (7.89 kg/m 3) was also observed under the PCI + M 1 treatment; PCI produced the best biological biomass yield, WUE and IWUE in comparison to DI and SDI systems. Accordingly, the PCI system could be a viable alternative to drip irrigation for areas with scarce water resources, particularly for smallholder farmers.

O objetivo deste trabalho foi determinar o consumo de água da cultura do pimentão, híbrido Magali R., cultivado em ambiente protegido durante um ciclo de 120 dias utilizando lisímetros de lençol freático constante. As informações climatológicas foram coletadas em estação meteorológica automática instalada no interior do ambiente protegido situado na Universidade Estadual de Maringá, em Maringá, PR, Brasil (23º25'57'' S e 51º57'08'' W) sendo que a evapotranspiração de referência foi estimada pelo método de Penman-Monteith e a evapotranspiração da cultura foi mensurada por meio de dois lisímetros de lençol freático constante construídos dentro do ambiente protegido. O consumo máximo da cultura para as condições edafoclimáticas de Maringá, durante um ciclo de 120 dias, foi de 5,37 mm d-1 com média de 2,35 mm d-1 e consumo total de 282 mm.

The aim of the present research is to discuss Tomsk Polytechnic University in respect of forming engineers' sociocultural competence and teaching engineering ethics. Today international standards of training engineers cover efficient communication skills, ability to understand societal and environment context, professional and ethical responsibility. This article deals with the problem of contradiction between the need to form engineers' sociocultural competence in Russian higher education institutions in order to meet the requirements of international accreditation organizations and the real capabilities of existing engineering curricula. We have described ethics teaching experience of TPU, studied the engineering master programs of TPU to see how the planned results are achieved. We have also given our recommendations to alter the structure of TPU educational curricula, which can also be applied in other higher education institutions.

To improve the scheduling of irrigation for low-density olive trees (Olea europaea L.) grown in a typical Mediterranean environment of Southern Portugal, and to clarify the mechanisms of water uptake by trees, transpiration, soil water status and stomatal response to water deficit were measured in an olive orchard. Olive trees of cv. Cordovil were subject to three irrigation treatments: full-rate irrigation, sustained deficit irrigation (SDI) providing for approximately 60% of water applied at full-rate irrigation, and a regulated deficit irrigation (RDI) with water applied at periods during three critical phases: before-flowering, at beginning of pit-hardening, before crop-harvesting to replenish soil moisture to field capacity. There was also a dry-farming treatment. Trees responded differently to summer rainfall and irrigation water: full-rate irrigation, which received 880 mm of irrigation and 240 mm of rainfall, used 704 mm for transpiration; SDI, which received the same amount of rainfall and 448 mm of irrigation water, used 745 mm of water for transpiration; RDI, which received 69 mm of irrigation water and 240 mm of rainfall, used 638 mm of water for tree transpiration; dry-farming, which received no irrigation, benefited from 240 mm of summer and early autumn rain and used 404 mm of water for transpiration. The results support the hypothesis that trees under RDI and dry-farming satisfy most of their early atmospheric evaporative demand by extracting water from outside of the area wetted by drip irrigation. Scaled-up orchard transpiration was used to define orchard crop and water stress coefficients. With full-rate irrigation and SDI the results showed that during summer droughts olive trees slow down their physiological mechanisms to conserve water, regardless of amount applied. The derived crop coefficient results also indicated that SDI was the most appropriate for scheduling the irrigation of cv. Cordovil orchards in Southern Portugal although applying RDI helped sustain orchard transpiration and yields. Irrigation accounted for 11% of total water used in transpiration, with the balance extracted by roots in the large volume of soil lying in the areas between the trees. However, using the RDI scheme to schedule irrigation appears to be appropriate only in wet years with well distributed late summer rainfall or where there is a shortage of farm irrigation water. In general, and particularly in years with no summer and early autumn rains as can often occur in this region, the SDI regime appears to be more appropriate for scheduling irrigation.

Due to the scarcity of water resources in Northwest China, the use of deficit irrigation scheduling is beneficial for sustainable agricultural development. Therefore, a 2-year field experiment was performed to investigate the effects of regulated deficit irrigation (RDI) on the yield and water productivity (WP) of drip-irrigated chili pepper plants in a typical arid environment of Northwest China. The results indicate that RDI strategies reduced actual crop evapotranspiration by 2-27%. Crop coefficients for chili pepper averaged 0.85, 1.09 and 0.84 for the development, middle and late stages, respectively. The highest yield occurred under full irrigation. The largest yield reduction (13-20%) was recorded when water deficit occurred during the middle stage. Fifty percent water deficit reduced yields more than 25% water deficit did. The highest irrigation water productivity and WP were achieved when water deficit occurred during the late stage. RDI may improve fruit quality by increasing the content of total soluble solids of the fresh fruit. In conclusion, full irrigation is recommended first for achieving the highest yield, and a water deficit of 25-50% during the late stage is also recommended if considering economic benefits and WP in the study region.

Seasonal rainfall in the Philippines is known to be modulated by ENSO phenomenon, with El Niño frequently contributing to reduced rainfall and drought while La Niña resulting in excessive rainfalls, floods and more intense typhoons. The alterations in rainfall patterns can have considerable feedback on solar radiation, air temperature, and soil moisture which can affect the ecosystem CO 2 exchange. In this paper, we assessed the effects of the ENSO events (2008-mid 2010) on the seasonal climate conditions and determined how it affected the gross primary production (GPP), ecosystem respiration (Re), and net ecosystem production (NEP) of two contrasting rice environments: flooded and non-flooded. The 2008 dry season (DS) was under a La Niña event while the 2008 wet season (WS) was a neutral one with strong tropical cyclones associated during the wet season. The 2009DS was also La Niña while the 2009WS was El Niño; however, the northern part of the Philippines experienced strong tropical cyclones. The 2010DS was under an El Niño event. The La Niña in 2008DS resulted in about 15% lower solar radiation (SR), 0.3 • C lower air temperature (T a) and 60% higher precipitation compared to the 28-year climate normal patterns. Both flooded and non-flooded rice fields had lower NEP in 2008 DS (164 and 14 g C m −2 , respectively) than in 2008 WS (295 and 82 g C m −2 , respectively) because the climate anomaly resulted in SR-driven decrease in GPP. The La Niña in 2009DS even resulted in 0.2 • C lower air temperature and 40% more precipitation than the 2008DS La Niña. This cooler temperature resulted in lower Re in flooded rice fields while the higher precipitation resulted in higher GPP in non-flooded fields since the climate was favorable for the growth of the aerobic rice, the ratoon crops and the weeds. This climate anomaly benefitted both flooded and non-flooded rice fields by increasing NEP (351 and 218 g C m −2 , respectively). However, NEP decreased in 2009WS in both flooded and non-flooded rice fields (225 and 39 g C m −2 , respectively) due to the devastating effects of the strong tropical cyclones that hit the northern part of the Philippines. On the other hand, the El Niño event during 2010DS resulted in about 6% higher solar radiation, 0.4 • C higher air temperature and 67% lower precipitation than the 28-year climate normal pattern. The NEP of flooded and non-flooded rice fields were closely similar at 187 and 174 g C m −2 , respectively. This climate anomaly resulted in T a-driven increase in Re, as well as vapor pressure deficit (VPD)-driven decrease in GPP in flooded rice fields. The GPP and Re in non-flooded rice fields were less sensitive to higher VPD and higher T a , respectively. It appears that the net ecosystem CO 2 exchange in non-flooded rice field was less sensitive to an El Niño event.

A growing scarcity of irrigation water could progressively lead to changes in rice production to systems using less irrigation water for rice or more crop diversification. A shift from current production of rice on flooded soils to production of rice on non-flooded soil with water-saving irrigation or to production of more water-efficient crops will have profound effects on carbon, water, and energy exchanges. This study used the eddy covariance technique to examine C uptake and water use efficiencies for watersaving, dry-seeded rice production and production of hybrid maize under overhead sprinkler irrigation as an alternative to flooded rice during two growing seasons. Maize with its C 4 physiology has greater photosynthetic capacity than rice. In 2011, maize had 1.4 times higher net C uptake than rice and twice as much grain yield as rice (10.4 vs 5.3 Mg ha −1). In 2012, lower solar radiation due to increased cloudiness and heavy rainfall during critical growth stages (late vegetative to early reproductive) decreased LAI and resulted to about 20% less net C uptake and maize yield (8.2 Mg ha −1), but the rice yield was unchanged (5.3 Mg ha −1) presumably because of improved crop management which included effective crop establishment at lower seed rate and efficient N application using fertigation. Canopy light use efficiency, crop water productivity (WP ET), and photosynthetic water use efficiency were 1.8, 1.9, and 1.6 times higher for maize than rice, respectively, despite sensitivity of maize to excess water. Net C uptake, evapotranspiration, and WP ET of dry-seeded rice under overhead sprinkler irrigation were comparable to those reported elsewhere for flooded rice. Average total water input (irrigation + rainfall) for rice was only 908 mm, as compared to 1300-1500 mm reported in literature for typical puddled transplanted rice.

Locally measured crop coefficients (K c) are critical for accurately quantifying and evaluating crop evapotranspiration (ET c) under local climate, soil, and crop management practices. Data and information on winter wheat K c values do not exist in Nebraska and are limited in the U.S. Great Plains in general. The objectives of this research were to measure ET c rates and develop growth-stage-specific single (normal) (K c) and basal (K cb) crop coefficients for winter wheat (Triticum aestivum L.) to provide data and information to producers, their advisors, and state and federal water regulatory and management agencies about the water use dynamics of winter wheat. Field experiments were conducted during two consecutive winter wheat growing seasons in

This paper presents a real-time, on-farm irrigation scheduling software (RIDECO). The software was been designed for stone fruit orchards in the semiarid conditions of Spain. The characterization of stone fruit crop water requirements for the local conditions and under different irrigation strategies is presented. Meteorological data in the study area is collected daily from the SIAR public network of weather stations in an automated fashion. Subsequently, values of cumulative degree-days are computed to identify the stages of fruit growth and crop development. The software allows performing weekly irrigation schedules under standard, regulated deficit irrigation and water restriction conditions. The irrigation scheduling software stands as a valuable tool for on-farm water resources allocation planning. It can be used to forecast the irrigation water

DETERMINAÇÃO DO COEFICIENTE DE CULTURA DO CAPIM-MOMBAÇA MANEJADO EM DIFERENTES ESTAÇÕES DO ANO NO SEMIÁRIDO MINEIRO   VIRGÍLIO JAMIR GONÇALVES MOTA¹; ABNER JOSÉ DE CARVALHO2; FLÁVIO GONÇALVES OLIVEIRA3; VIRGÍLIO MESQUITA GOMES4; FLÁVIO PINTO MONÇÃO5 E VIRGÍLIO JAMIR GONÇALVES MOTA FILHO6   1 Eng. Agrônomo, Doutor, Prof. DCA/UNIMONTES, Campus Janaúba – MG. Av. Reinaldo Viana, 2630, Janaúba - MG, 39440-000, Brasil. e-mail: virgilio.mota@unimontes.br 2 Eng. Agrônomo, Doutor, Prof. DCA/UNIMONTES, Campus Janaúba – MG. Av. Reinaldo Viana, 2630, Janaúba - MG, 39440-000, Brasil. e-mail: abner.carvalho@unimontes.br 3 Eng. Agrícola, Doutor, Instituto de Ciências Agrárias, Universidade Federal de Minas Gerais. ICA/UFMG, campus Montes Claros-MG, Brasil. flagiogoliveira@ibest.com.br 4 Eng. Agrônomo, Doutor, Prof. DCA/UNIMONTES, Campus Janaúba – MG. Av. Reinaldo Viana, 2630, Janaúba - MG, 39440-000, Brasil. e-mail: virgilio.gomes@unimontes.br 5 Zootecnista, Pós-Doutor, Prof. colaborador do PGZ/DC...

Locally measured crop coefficients (K c) are critical for accurately quantifying and evaluating crop evapotranspiration (ET c) under local climate, soil, and crop management practices. Data and information on winter wheat K c values do not exist in Nebraska and are limited in the U.S. Great Plains in general. The objectives of this research were to measure ET c rates and develop growth-stage-specific single (normal) (K c) and basal (K cb) crop coefficients for winter wheat (Triticum aestivum L.) to provide data and information to producers, their advisors, and state and federal water regulatory and management agencies about the water use dynamics of winter wheat. Field experiments were conducted during two consecutive winter wheat growing seasons in

Кызылординского университета имени Коркыт Ата BULLETIN of the Korkyt Ata Kyzylorda University №4 (63) 2022 1-БӨЛІМ АУЫЛ ШАРУАШЫЛЫҒЫ ҒЫЛЫМДАРЫ «Ауыл шаруашылығы ғылымдары» ғылыми бағыты Қазақстан Республикасы Білім және ғылым министрлігі Білім және ғылым саласында cапаны қамтамасыз ету комитеті Ғылыми еңбектің негізгі нәтижелерін жариялау үшін ұсынатын ғылыми басылымдар тізбесіне енген (21.02.2022 ж. № 63 бұйрық). Л.А.Тохетова-жауапты редактор, ауыл шаруашылығы ғылымдарының докторы, доцент Редакция алқасы К.Н.Тодерич PhD, Тоттори Университеті, Жапония; Ш.С.Рсалиев биология ғылымдарының докторы, доцент, «Қазақ егіншілік және өсімдік шаруашылығы ғылыми-зерттеу институты» РМК, Қазақстан Республикасы; Б.А.Дуйсембеков биология ғылымдарының кандидаты, доцент, «Агропарк Оңтүстік» ЖШС, Қазақстан Республикасы; А.С.Рсалиев ауыл шаруашылығы ғылымдарының кандидаты, «Биологиялық қауіпсіздік проблемалары ғылыми-зерттеу институты» ЖШС, Қазақстан Республикасы. СЕЛЬСКОХОЗЯЙСТВЕННЫЕ НАУКИ Научное направление "Сельскохозяйственные науки" включена в перечень научных изданий, рекомендуемых комитетом по обеспечению качества в сфере образования и науки Министерства образования и науки Республики Казахстан для публикации основных результатов научного труда (приказ № 63 от 21.02.2022 г.). Л.А.Тохетова-ответственный редактор, доктор сельскохозяйственных наук, доцент Редакционная коллегия К.Н.Тодерич PhD, Университет Тоттори, Япония; Ш.С.Рсалиев доктор биологических наук, доцент, РГП «Казахский научно-исследовательский институт земледелия и растениеводства», Республика Казахстан; Б.А.Дуйсембеков кандидат биологических наук, доцент,ТОО «Агропарк Оңтүстік», Республика Казахстан; А.С.Рсалиев кандидат сельскохозяйственных наук, ТОО «Научно-исследовательский институт проблем биологической безопасности», Республика Казахстан. AGRICULTURAL SCIENCES The scientific direction "Agricultural Sciences" is included in the list of scientific publications recommended by the Committee for Quality Assurance in the field of education and Science of the Ministry of Education and Science of the Republic of Kazakhstan for the publication of the main results of scientific work(Order No. 63

The results of this study revealed that the pan evaporation and sensor based irrigation scheduling along with fertigation scheduling significantly affected the plant height, fruit weight, fruit length, crop water requirement, crop yield and water use efficiency of okra crop. The pan evaporation and crop evapotranspiration (ETc) values significantly vary over different stages of okra crop. The maximum and minimum average daily pan evaporation was recorded 8.4 mm day-1 and 4.5 mm day-1 at mid stage and late stage of okra crop respectively while, the maximum average daily ETc was recorded 7 mm day-1 at mid stage of okra crop. A approach of irrigation scheduling with 100 per cent field capacity, based on soil moisture sensor under automated drip irrigation system along with 100 per cent RDF through fertigation in equal splits at 4 day intervalor 80 % per cent of volume of crop water requirement based on pan evaporation under automated drip irrigation along with 100 per cent RDF through ...

The monitoring of crop production and irrigation at a regional scale can be based on the use of ecosystem process models and remote sensing data. The former simulate the time courses of the main biophysical variables which affect crop photosynthesis and water consumption at a fine time step (hourly or daily); the latter allows to provide the spatial distribution of these variables over a region of

The impact of water quality with varying deficit irrigation level on the plant biomass and fruit quality parameters of greenhouse tomato (Lycopersicon esculentum L. cv Izmir) was investigated. A pot-based experiment was carried out over two growing seasons (2017-2018 and 2018-2019). Three water qualities: groundwater, recycled wastewater and an equal mix of both were applied in four irrigation scenarios which aimed to maintain soil moisture levels at 60%, 70%, 80% and 100% of field capacity. A surface drip irrigation system was designed maintaining irrigation frequency of two days. Results showed that both water quality and deficit irrigation significantly affected plant biomass. The fresh fruit weight was rather uniform, ranged from 53.2 to 85.4 gram and found highest in full irrigation. Most of the fruit quality parameters were not significantly affected by water quality.The significantly higher values of total soluble solid (7.87 degree brix), fruit firmness (9.28 kg/cm 2), fruit pH (4.24) and vitamin C content (68.33 mg/kg) were measured in treatments maintaining soil moisture content at 60% of field capacity (most water-stressed conditions). Based on these findings, it recommended that by adopting deficit irrigation and maintaining soil moisture at 60% of field capacity, fruit quality parameters can be significantly improved. In contrast, fresh fruit weight and plant biomass were reduced.

This paper describes the methodology developed and implemented for Remote Sensing DataBase (RSDB) preparation from multitemporal and multi-sensor data from Indian earth observation satellites. The characteristics of the RSDB prepared over parts of Indo-Gangetic Basin and Central India (IGB&CI) are summarised. An approach for extraction of long term (1988-89 to 2004-05) Land Use / Land Cover (LULC) changes using RSDB over selected sites is demonstrated. Design of analysis framework and selection of a suitable projection scheme with optimization of scale factors has been discussed. The major components of procedure are multi-date RS data geo-referencing, radiometric normalization, top of atmosphere (TOA) reflectance images preparation, multi-image compositing and mosaicing. An RSDB for three rabi (winter) seasons i.e. 1988-89 (226 IRS 1A LISS-II quadrants), 1993-94 (251 IRS 1B LISS-II quadrants) and 2004-05 (three bi-monthly sets, 170 IRS P6 AWiFS quadrants) has been prepared over IGB...

Estimation of evapotranspiration (ET) is an important part of agricultural water management, in local and regional water balance studies and in hydrological modelling. At the field scale ET is important in irrigation planning and scheduling and is an integral part of field management decision support tools (Hansen et al., 1991; Plauborg and Olesen, 1991; Abrahamsen and Hansen, 2000). An accurate estimation of ET includes integration of a number of factors such as crop characteristics and development stage, weather parameters and environmental conditions and management practices. For operational use equations to estimate ET have been developed. The Food and Agriculture Organization (FAO) of the United Nations adopted a two-step methodology (Jensen et al., 1990; FAO, 1990; Allen et al., 1998). Following this approach reference evapotranspiration (ET 0) is calculated for a grass reference crop, which subsequently is related to ET from the crop using empirical crop coefficients. ET 0 is a theoretical amount of water exchanged between the atmosphere and a

Lowland irrigated rice is the predominant crop produced in the Senegal River Valley characterised by very low annual rainfall, high temperatures, and low relative humidity. The Senegal River is shared by Senegal, Mali, Mauritania, and Guinea, and serves as the main source of irrigation water for the adopted double rice cropping system. Developing appropriate resource management strategies might be the key factor for the sustainability of rice production in the region. This study aims to estimate rice seasonal evapotranspiration (ETa), irrigation water requirement, and to develop rice growth stage specific crop coefficients (Kc) to improve rice water productivity. Field experiments were conducted during the hot and dry seasons in 2014 and 2015 at the AfricaRice research station at Fanaye in Senegal. Irrigation water inputs were monitored and actual crop evapotranspiration was derived using the water balance method. Daily reference evapotranspiration (ETo) was estimated using the Penman-Monteith equation and the weather variables were collected at the site by an automated weather station. The results showed that the ETo during the hot and dry season from February 15 th to June 30 th varied from 4.

The monitoring of crop production and irrigation at a regional scale can be based on the use of ecosystem process models and remote sensing data. The former simulate the time courses of the main biophysical variables which affect crop photosynthesis and water consumption at a fine time step (hourly or daily); the latter allows to provide the spatial distribution of these variables over a region of

The ASCE Evapotranspiration in Irrigation and Hydrology Committee in cooperation with the Water Management Committee of the Irrigation Association has defined and established a standardized reference evapotranspiration (ET) equation. The purpose of the equation and standardized calculation of parameters is to bring a commonality to the methodology of reference ET and to the basis used to determine crop coefficients for both agricultural and landscape use. Issues and requirements in the selection and definition of the standardized procedure are that the procedure be understandable, defensible, accepted by science/engineering communities, relatively simple, and use existing and historical data and technology. The primary challenge was to select one or more equations that would satisfy the selection criteria. There have been traditionally two types of reference crops (grass and alfalfa) and six major reference equation types (Kimberly Penman, CIMIS 2 Penman, FAO Penman, ASCE Penman-Monteith, FAO-56 Penman-Monteith and NRCS Penman-Monteith) have evolved over the past thirty years, each having large groups of followers and related crop coefficients. In addition, the reference crop is a living crop and therefore changes in its height, leaf area, stage of growth, age, variety, stomatal feedback, and irrigation frequency impact its ET rate. Other challenges include a myriad of procedures used to predict net radiation, vapor pressure deficit and other equation parameters. Hourly and daily computation are both in common usage, therefore, it is important that hourly calculations, when summed for 24 hours agree relatively closely with calculations made on daily time steps.

The command area management of a dam includes various parameters to studied i.e. ground water recharge, irrigation intensity, water use efficiency (WUE) knowing land use pattern, various thematic maps etc. These parameter are estimated using some calculation and by generating maps using Remote sensing and Geographical system (GIS). The software model used in this study is ArcGIS 9.3. The thematic maps of command area shows the land use pattern, canal network, village boundary, ground water level depth of Karjan dam command area.

We used eddy covariance to measure energy fluxes in an irrigated rice-rice ecology. • Mean latent heat flux dominated over sensible heat flux in both surface and canopy. • Energy balance measured by residual heat flux distinctively explained closure. • Much variation was not found in energy balance ratio after storage terms inclusion.

We used eddy covariance to measure energy fluxes in an irrigated rice-rice ecology. • Mean latent heat flux dominated over sensible heat flux in both surface and canopy. • Energy balance measured by residual heat flux distinctively explained closure. • Much variation was not found in energy balance ratio after storage terms inclusion.

Accurate quantification of crop water use or evapotranspiration (ET) is crucial in agriculture for improved irrigation scheduling and water resource planning across a wide range of farming conditions. The aim of this study was to quantify ET dynamics for irrigated sweet potato (Ipomoea batatas) in order to determine the FAOtype single crop coefficients (K c) that can be used in models to estimate crop water use under a wider range of semi-arid climatic conditions. An open-path eddy-covariance system containing energy balance sensors was installed in a 1.3 ha field to estimate ET of orange-fleshed sweet potato. The study was conducted during the 2014/15 and 2015/16 growing seasons. Daily ET varied between 0.5 and 5.5 mm (linked closely to canopy cover and weather conditions), with total seasonal measured ET of 361 and 347 mm for the 2014/15 and 2015/16 seasons, respectively. Time-averaged K c values of 0.47 for the initial stage, 0.97 for the mid-season stage and 0.44 for the late growth stage were derived from this study. In addition, a heat unit based Growing Degree Days-K c equation was successfully developed and validated in this study to adjust K c values of sweet potato to specific climates. These K c values can be used in combination with the FAO-56 reference evapotranspiration (ET o) to estimate site-specific sweet potato ET, which is vital for improving water management of irrigated sweet potato cropping systems growing under semi-arid conditions.

automatic weather station. The daily crop evapotranspiration (ETc) was measured by three weighing lysimeters of load cells. Aiming high fruit yield in this region, we recommend that the following local values of Kc and Kcb be used for planning and management of irrigation, respectively: initial stage (crop establishment)-0.34 and 0.24; intermediate stage (growth and fruit maturation)-1.16 and 1.10; end stage (harvest)-0.93 and 0.86. These Kc values of initial and intermediate phases are statistically higher than the values of Kc and Kcb already adjusted according to the methodology presented in the FAO Irrigation and Drainage Paper 56. The values of Kc and Kcb at the end phase are not statistically different from the FAO values.

The crop coefficient (K c) values of rice paddy are important for estimating accurate rice crop evapotranspiration (ET c), water transfers planning, efficient irrigation management, and hydrological studies. In this study, ET c was measured and a generalized K c curve was calculated for paddy rice in the Sacramento Valley, California. Field experiments were conducted in three rice paddy fields during the 2011-2013 growing seasons. Surface renewal analysis, after calibration using eddy covariance method, was applied to obtain sensible heat flux values from high-frequency temperature readings; latent heat flux densities were characterized by the residual of the energy balance method. The results revealed that there is considerable variability in rice water use both spatially and temporally. The average 3-year measured seasonal ET c of the experimental fields ranged from 690 to 762 mm in Butte County and from 681 to 813 mm in the Colusa County. A mean daily seasonal ET c of 5.3 mm d −1 and midseason ET c of 5.8 mm d −1 was observed. The rice K c values were lower than those commonly used to estimate rice ET c during the midseason and were greater than expected during early growth before canopy closure. For a typical growing season of 145 days, the K c values were estimated as 1.10, 1.00, and 0.80 for the initial-growth, midseason, and late-season stages, respectively. The generalized K c curve is quite accurate for practical application and enables growers to determine rice crop water use in a reliable, usable, and affordable format. The proposed K c information can be used to refine the estimates of rice consumptive water use in the Sacramento Valley for the purpose of water transfers to water-short areas of the State. These K c values are likely applicable to other locations having similar climate to the Sacramento Valley in California.

Crop coefficient (K c)-based estimation of crop water consumption is one of the most commonly used methods for irrigation management. Spectral modeling of K c is possible due to the high correlations between K c and the crop phenologic development and spectral reflectance. In this study, cotton evapotranspiration was measured in the field using several methods, including eddy covariance, surface renewal, and heat pulse. K c was estimated as the ratio between reference evapotranspiration and the measured cotton evapotranspiration. In addition, a time series of Sentinel-2 imagery was processed to produce 22 vegetation indices (VIs) based on the sensor's unique spectral bands. Empirical K c-VI models were derived and ranked according to their prediction error. In accordance with previous studies, we found a strong correlation between the normalized difference vegetation index (NDVI) and K c (R 2 = 0.94), and yet, we also identified other spectral indices that are more strongly correlated to K c. The indices that were found to be the most suitable for K c prediction were based on the red and red-edge bands (MTCI, REP, and S2REP). This progress in estimating cotton water consumption using satellite imagery that are available at no cost is a leap forward towards the development of crop irrigation requirements models. Consequently, this work sets the scene for near-real-time irrigation decision support systems.

A method has been developed to obtain the crop irrigation needs of an irrigated area of ​​about 140,000 hectares, Las Vegas del Guadiana in Extremadura, Spain. For this, semi-hourly and daily meteorological information from the SIAR_REDAREX network, the PAC crop declaration for the year 2021 and Sentinel2 satellite images have been used. Crop coefficients, Kc,  have been derived from the NDVI vegetation index. The calculation has been made independent by crop type

Contar con valores observados de radiación neta, de flujos de calor sensible y latente en el aire, y del flujo de calor en el suelo para diversos usos de suelo permite ajustar y validar modelos atmosféricos. En este trabajo se presentan dichos flujos estimados sobre una cobertura de trigo en el sudeste de la región pampeana argentina. El análisis de la información obtenida muestra que tanto los flujos turbulentos de calor sensible y latente, como el flujo de calor en el suelo presentan una variabilidad asociada tanto a las condiciones atmosféricas como al estado de desarrollo del cultivo. Estos comportamientos están principalmente determinados por la disponibilidad de energía en el sistema modelado a través de la radiación neta, y también por la variabilidad de la estructura de la cobertura causada por variaciones en los estadios fenológicos de la misma. Los resultados mostraron una correlación entre valores máximos del flujo de cantidad de movimiento y calor latente. Durante las fases vegetativas y de floración el flujo de calor latente domina ampliamente la partición de energía, mientras que durante el llenado y maduración de frutos su rol es menor, y cobran mayor importancia los flujos de calor sensible y en el suelo. Palabras claves: Balance de energía, flujos turbulentos, trigo, Provincia de Buenos Aires.

In the present study on winter crop growth monitoring in different villages in Kapadvanj Taluka of Kheda district was carried out using multi-temporal Sentinel-2 multi-spectral data (spatial resolution 10-m). Multi-temporal Sentinel-2 data covering study area for the winter crop period from November-2018 to March-2019 was downloaded from https://earthexplorer.usgs.gov/. The major objective of this study was to monitor site-specific crop growth in different villages of Kapadvanj Taluka by generating Normalized Difference Vegetation Index (NDVI) profiles of major winter crops. The spectral behavior of wheat, potato, bajara and castor crops during active growth stages was studied and it was observed that the spectral response of wheat and potato crops have quite distinct spectral behavior. However, castor and bajara crops do not show distinct spectral behavior. In this study, from the NDVI profiles of different crops it was observed that very distinct growth stages like early growth st...

Measurements of CO2 flux (FCO2) and H2 O flux (FH2O) were carried out on paddy fields of Thailand and Japan during the 2004, 2005 and 2006 growing seasons using the Bowen ratio technique. The objective was to determine the water resource requirement to achieve a certain amount of CO2 assimilation per land area and analyze the ratio between FCO2 and FH2 O (CWFR = FCO2/FH2O). The relationship between FCO2 and FH2O was investigated using regression analysis in 4 growing stages. Relatively high correlations (r 2 = 0.56 0.96, p < 0.01) between FCO2 and FH2O were found when data were grouped by growing stage. Using daytime average data, there was high correlation (r 2 = 0.61 0.94, p < 0.01) between daytime average CWFR (CWFRd) and daytime average vapor pressure deficit (VPDd) in paddy fields of Japan and Thailand for each growing stage. Pooled data from Thailand and Japan showed high correlations (r 2 = 0.61 0.94, p < 0.01) between CWFRd and VPDd for each growing stage. The developed regression equation was tested using an independent published dataset, and it was found that the estimation error was only 2.7%. The regression equations will be useful for estimating CWFRd by only VPDd and accordingly for assessing the water resource requirement.

Evapotranspiration (ETR), reference evapotranspiration (ET0), and seasonal ETR totals were determined for soybean over two growing seasons, at Keszthely, Hungary, using traditionally operated and converted evapotranspirometers. The study aimed to document the plant–water response of two soybean varieties (Sinara: Sin; Sigalia: Sig) which have different water demands. Three water supply treatments were tested: unlimited (WW) watering, 50% of crop water requirement (RO), and rainfed (P). Reconstructed evapotranspirometers allowed crop water deprivation to be simulated under field conditions. ETR sums were higher during the cooler 2017 than in the warmer 2018, calling attention to the importance of being informed about more detailed meteorological variables other than monthly (seasonal) means. In addition to variation in daily mean air temperatures (Ta), maximum Ta played a key role in determining ETR under naturally occurring extreme weather conditions in 2018. Irrespective of the var...

Ақмола облысының құрғақ далалы аймағында өсетін бір жылдық мал азықтық дақылдардың өсу кезеңіне және дамуына байланысты көк балаусаның химиялық құрамы келесідей аралықта, яғни шикі протеин 2,3-тен 3,1% - ға дейін, шикі жасұнық 7,1-ден 10,8% - ға дейін, шикі май 0,5-тен 0,9% - ға дейін, шикі күл 1,6-дан 2,7% - ға дейін, АЭЗ 9,1-ден 15,9% - ға дейін, ал пішеннің химиялық құрамы тиісінше 7,7-ден 11,8% - ға дейін, 27,8-ден 38,9% - ға дейін, 2,7-ден 9,3% - ға дейін, 7,5-тен 11,6% - ға дейін, 41,8-ден 46,7% - ға дейін өзгерді. Бір жылдық мал азықтық дақылдардың тіршілік кезеңіне қарай көк балаусадағы жасұнықтың мөлшері түтікке шығу кезеңінде 7,1-ден 8,4% - ға дейін, шашақтану кезеңінде 7,6-дан 8,4-ке дейін, гүлдену кезеңінде 8,6-дан 10,8% - ға дейін, ал пішенінде тиісінше 27,8 - ден 32,8% - ға дейін, 32,1-ден 37,6-ға дейін, 33,9-дан 38,9% - ға дейін өзгерді. Көк балаусадағы шикі протеиннің мөлшері түтікке шығу кезеңінде 2,7-ден 3,1% - ға дейін шашақтануда 2,8-ден 3,1-ге дейін, гүлдену кез...

The deficit irrigation offers water savings potential that is becoming popular in arid and semi-arid regions reducing freshwater use over time. A two-year factorial experiment was conducted to evaluate growth, yield and water productivity of tomato under water deficit irrigation of the drip and furrow method. The experiment was carried out in a split-plot design with drip irrigation and furrow irrigation as main plot treatments, and soil moisture regimes (0, -10, -20, -30 kPa) as subplots. Data were collected on growth parameters, physiological traits, yield and water productivity of tomato. The results showed that physiological traits, yield, and water productivity were significantly influenced by irrigation system and soil moisture regime. The drip irrigation system with -10 kPa soil moisture regime reduced total water input by 22.6% and 19.8% and gave 28% and 22% higher fruit yields in 2020 and 2021, respectively, compared with furrow irrigation system. Plant growth was higher an...

MODELO PARA ESTIMATIVA DO RENDIMENTO DE CULTURAS IRRIGADAS BASEADO NO BALANÇO HÍDRICO SEQUENCIAL: APRESENTAÇÃO E APLICAÇÃO     MARCO ANTÔNIO JACOMAZZI1; JOSÉ ANTONIO FRIZZONE2; ASDRUBAL JESUS FARIAS RAMIREZ3; MARIA ALEJANDRA MORENO-PIZANI4; FABIO TOMASELLA JOHANSSON5 E SERGIO NASCIMENTO DUARTE6   1-Mestrado Profissional em Rede Nacional em Gestão e Regulação de Recursos Hídricos - ProfÁgua, Universidade Federal do Rio Grande do Sul – UFRGS, Av. Bento Gonçalves, 9500, 91501-970, Porto Alegre/RS, (19) 98156-4809, marcoantono@rasa.eng.br 2 Departamento de Engenharia de Biossistemas, Escola Superior de Agricultura “Luiz de Queiroz”, Av. Pádua Dias nº11, Bairro São Dimas, Piracicaba – SP, Brasil, CEP: 13.418-900, frizzone@usp.br 3 RASA Engenharia, Edifício Racz Center, R. Alfredo Guedes nº 1949, sala 506, Higienópolis, Piracicaba- SP, cep: 13.419-080, Brasil, ajfara@gmail.com. 4 PECEGE, R. Alexandre Herculano, nº 120, T6, Vila Monteiro, Piracicaba – SP, cep: 13.418-455, Brasil, morenom76...

The results of this study revealed that the pan evaporation and sensor based irrigation scheduling along with fertigation scheduling significantly affected the plant height, fruit weight, fruit length, crop water requirement, crop yield and water use efficiency of okra crop. The pan evaporation and crop evapotranspiration (ETc) values significantly vary over different stages of okra crop. The maximum and minimum average daily pan evaporation was recorded 8.4 mm day-1 and 4.5 mm day-1 at mid stage and late stage of okra crop respectively while, the maximum average daily ETc was recorded 7 mm day-1 at mid stage of okra crop. A approach of irrigation scheduling with 100 per cent field capacity, based on soil moisture sensor under automated drip irrigation system along with 100 per cent RDF through fertigation in equal splits at 4 day intervalor 80 % per cent of volume of crop water requirement based on pan evaporation under automated drip irrigation along with 100 per cent RDF through fertigation in equal splits at 2 day interval, can be used for irrigating okra crop with significant water saving, crop yield and water use efficiency under limited availability of daily weather datain climatic condition of Udaipur district of Rajasthan.

Rice is an important food crop cultivated all over the world and in India. There are different factors such as temperature, relative humidity, rainfall and solar radiation are influencing on rice crop production. Not only these factors, but also, some of the micro climatic factors such as canopy temperature, leaf temperature, soil temperature and stomatal conductance are also influencing on crop production. Microclimate, which refers to the climatic factors in the immediate proximity of the plants it controls and influences the physiological responses of the plants as well as the activities of energy exchange between the plant and its surroundings. It is expected that increased year-to-year yield variability in crop production will result from an increase in the frequency and severity of droughts and floods, as well as from irregular precipitation patterns.In order to promote food security and agricultural sustainability in this changing climate, it is necessary to use such microcli...

Accurate estimation of crop water requirements (ETc) of any crop is essentially for irrigation scheduling and water management. The present study was undertaken to estimate the crop water requirement (ETc) of maize crops grown in winter seasons in middle Gujarat region of Panam command area Gujarat. The daily reference evapotranspiration (ETo) was estimated by FAO Penman-Monteith method using 11 years (2006 to 2016) mean meteorological data of Panam command. The most common and practical approach widely used for estimating crop water requirement, and the operational monitoring of soil-plant water balance is the FAO-56 method. In the FAO-56 approach, crop evapotranspiration is estimated by the combination of a reference evapotranspiration (ETo) and crop coefficients. The Kc values for maize as given in FAO-56 was used in which Kcmid and Kcend were corrected for climatic conditions of stations. The corrected Kc values were used to calculate the daily crop water requirement (ETc) for maize crops grown at Panchmahal region. The results revealed that during winter season (15 October to 15 January) the mean daily (ETo) varies from 5.5 to 7.32 mm day-1. The mean water requirement of maize during initial stage is 1.085 mm day-1 , during developmental stage it varies between 1.085 to 4.35 mm day-1, and during the mid-season stage ETc varies between 4.35 to 5.76 mm day-1 and during late season stage it decreases upto 3.20 mm day-1. The seasonal water requirement of winter maize varies between 312.49 mm to 487.08 mm. This study established precise estimation of evapotranspiration which was the only beneficial water loss from the field. The information generated can be used in scheduling irrigation for winter season maize crops of Panchmhal region.

It is well known that crop coefficients are not necessarily transferrable from one location to another, for a variety of reasons. For example, the United Nations Food and Agricultural Organization (UN FAO) 24 publication on evapotranspiration listed ranges of midseason crop coefficients for particular crops, depending on wind speed and humidity. In the more recent UN FAO 56 publication, an equation was presented that adjusted crop coefficients for wind speed, humidity, and crop height. Climate correction is important for sharing and adjusting crop coefficient data. However, it was found that the FAO 56 equation gave inaccurate corrections for a crop having the same characteristics as the reference crop surface, and it is likely that it also will be inaccurate for other crop surfaces. Consequently, the aim of this research was to develop and test a new method to correct midseason crop coefficients for climate differences. Climate data were used from the California Irrigation Management Information System and a similar approach was used to develop standardized reference evapotranspiration equations for short and tall canopies, to develop and test the new method. The method estimates the aerodynamic resistance of crops in a base climate as an inverse function of wind speed. This function of wind speed was used in a modified Penman-Monteith equation to account for climate effects on midseason crop coefficients in nonbase climates. The methodology to account for climate data and estimate midseason crop coefficient values in a nonbase climate from base climate crop coefficients is presented in this paper.

Acquaintance of the exact water loss through actual evapotranspiration is necessary for sustainable development and environmentally sound water management to avoid the underestimation or overestimation of crop water consumption. An accurate estimation of crop evapotranspiration is important for better irrigation scheduling and water management. An attempt has been made to estimate actual evapotranspiration (ETa) at different growth stage of Bt. cotton under silver black plastic mulch, biodegradable plastic mulch, wheat straw mulch and no mulch condition using soil moisture sensor and it was compared with crop evapotranspiration (ETc) estimated using Penman-Monteith and Pan Evaporation method. Results revealed that Pan evaporation and Penmen Monteith approach over estimated cumulative ETc under by 46.11%, 45.84%, 39.33%, 56.10% and 22.89%, 22.50%, 13.19%, 39.42% than sensor based ETc under silver black plastic mulch, biodegradable plastic mulch, wheat straw mulch and control respectively at initial stage of Bt. cotton which was followed by development stage, mid stage and end stage of Bt. cotton. Sensor based approach estimated lower cumulative ETc at all growth stage than Penmen Monteith method and Pan ETc approach.

Most fundamental requirement of scheduling irrigation is the determination of crop evapotranspiration (ET c). Over estimation of crop evapotranspiration leads waste of scarce water and under estimation leads to the plant moisture stress and decreased crop yield. In order to avoid the underestimation or overestimation of crop water consumption, knowledge of the exact water loss through actual evapotranspiration is necessary for sustainable development and environmentally sound water management. The Penman-Monteith method is maintained as the single standard method for the computation of reference evapotranspiration (ET 0) from complete meteorological data but, it requires large number of climatic parameters that are not always easily available for many locations. Pan evaporation method is susceptible to the microclimatic conditions under which the pans are operating and the rigour of station maintenance. An attempt has been made to estimate actual evapotranspiration (ET a) of drip irrigated Bt. cotton under silver black plastic mulch using soil moisture sensor. ET a (ET c) at different growth stage of Bt. cotton was estimated using soil moisture sensor and it was compared with ET c estimated using Penman-Monteith and Pan evaporation method. Results revealed that Pan evaporation method and Penmen Monteith method over estimated ET c by 19.26% and 13.78% than sensor based ET c respectively. Sensor based method estimated lower cumulative ET c at initial stage, development stage, mid stage, and end stage by 46.11%, 33.70%, 18.83% and 17.93%, and 22.89%, 17.80%, 16.09% and 14.89%over Pan evaporation and Penmen Monteith method respectively.

An experiment was conducted at Research cum demonstration Farm, RTTC, Junagadh Agricultural University during year 2017-18 to determine crop coefficients of wheat (GW-366) under different land configurations (broad bed furrow L1 and flat land L2) and irrigation systems (drip irrigation S1 and surface irrigation S2) with two irrigation levels (1.0 ETc I1 and 0.8 ETc I2). Soil moisture sensors were installed to monitor daily fluctuations of soil moisture which were utilized to calculate actual crop evapotranspiration. Results revealed that adjusted FAO Kc predicts higher value than sensor based Kc values at both irrigation levels. Sensor based Kc-ini, Kc-dev, Kc-mid and Kc-end under flat land configuration with drip irrigation scheduled at 0.8 ETc were lower by 22.25%, 17.44%, 19.61% and 25.17% over adjusted FAO Kc-ini, Kc-dev, Kc-mid and Kc-end respectively and 51.35%, 30.42%, 16.81% and 28.80% over flat land configuration with surface irrigation at 1.0 ETc respectively. Broad bed furrow (BBF) land configuration with drip irrigation observed lower sensor based Kc-ini, Kc-dev, Kc-mid and Kc-end by 53.81%, 34.15%, 15.91% and 28.39% and 51.47%, 34.14%, 17.36% and 21.93% than flat land configuration with surface irrigation at 1.0 ETc and 0.8 ETc respectively. P-M ETc over estimated irrigation water by 106.18mm (38.28%) and 194.25mm (36.67%), 249.29mm (59.61%) and 89.43mm (30.40%), 49.23mm (19.11%) and 93.05mm (19.14%), and 153.54mm (40.36%) and 44.78mm (17.09%) than sensor based irrigation under L1S1, L2S2, L1S2 and L2S1 at I1 and I2 respectively. The results provide estimates of ET0, ETc and Kc for use in irrigation scheduling of wheat crop planted in Junagadh region or elsewhere with similar environmental conditions.

Reduced cost of cultivation (30%) and increase in yield (40%) obliged the Saurashatra farmers to adopt Bt. Cotton on mass scale. Saurashtra cotton earns more profit at international market due to good luster, low naps, more wax on fibers surface, very low dye absorption. High evaporative conditions, scarcity of groundwater, and deficient rainfall condition are detrimental to cotton yields. Climatic change is adding another dimension to this complex nexus of soil-water-plant-atmosphere. Adverse environmental conditions coupled with water scarcity intrigued farmers of this region to adopt drip irrigation with mulch in Bt. Cotton for mitigating the impact of climatic aberrations. Determination of actual crop evapotranspiration during crop growing season is highly advantageous for sound irrigation scheduling. So far no study is reported to develop crop coefficient for drip irrigated biodegradable mulch cotton subjected to variable irrigation regimes. An experiment was undertaken consecutively for two years (2013-14 and 2014-15) to address this issue. Diurnal and temporal variation of soil moisture with depth was monitored using soil moisture sensors at irrigation regimes 1.0 IW/ETc and 0.8 IW/ETc. The control treatment was taken as drip with no mulch. Adjusted FAO K c predict higher value than sensor based K c values at both irrigation regimes. Sensor based K c-mid values were lower by 12.99% and 30.04% than the adjusted FAO K c-mid value at 1.0 IW/ET c and 0.8 IW/ET c respectively. Biodegradable plastic mulch reduced K c-ini value by 72.26% and 66.54% over control at 1.0 IW/ET c and 0.8 IW/ET c respectively. Overestimated adjusted FAO K c values caused a loss of 78.13mm and 66.54mm of precious water at 1.0 IW/ET c and 0.8 IW/ET c respectively. This study admonishes blind adoption of published FAO K c curves, for mulch conditions.