Modeling Deficit Irrigation Effects on Maize to Improve Water Use Efficiency (original) (raw)
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Deficit irrigation improves maize yield and water use efficiency in a semi-arid environment
Agricultural Water Management, 2021
Uncertainty in the availability of water supply pose challenges to traditional irrigation approaches. Regulating the amount and time of irrigation at different crop growth stages could provide a solution to optimize the irrigation water amid drought periods. This study evaluated the effect of different deficit irrigation levels on maize (Zea mays L.) at several growth phases over two growing seasons (2012 and 2013) in Yangling, Shaanxi province of China. Total nine irrigation treatments incorporated three irrigation amount ratios, i.e., control irrigation (CK, 100 % of crop evapotranspiration), and 80 % and 60 % of control irrigation; named as T2-T9. Among the irrigation treatments, grain yield ranged from 6392 to 9362 kg ha-1 and seasonal water use efficiency (WUE) varied from 20.3 to 34.9 kg ha-1 mm-1 , whereas the irrigation water use efficiency (IWUE) ranged between 32.0 and 58.1 kg ha-1 mm-1. T2 that received 80 % irrigation between V8 and R6 growth stage had overall higher yield than CK, and this was closely followed by T4 that received 80 % irrigation at growth phase V3-V8 and V11-Tasseling, full irrigation at V8-V11, and 60 % irrigation between Tasseling and Maturity. Due to near optimum growing season temperature in 2013, larger WUE was noted in comparison to 2012, that resulted 16 % larger yield with 10 % lesser ETc, on an average, whereas 2012 growing season had better IWUE because of 37.5 % smaller irrigation consumption. Maize grain yield in response to water stress (Ky, the yield response factor) was 0.66, suggesting that the environmental conditions of the study area favor the application of deficit irrigation. The maize yield response to reduced irrigation supply in this experiment indicated that regulated deficit irrigation might help growers to cope with decline in water availability during growing season.
Soil in the Environment, 2015
The rapid decline of groundwater table is threatening sustainable irrigation agricultural development in the North China Plain (NCP). Optimized irrigation scheduling and water-saving irrigation technologies need to be developed to reduce irrigation water use and maintain the grain production potential for the region. This study was conducted at Luancheng experimental station in the NCP during 2012-2015 to evaluate the effects of different irrigation methods (basin irrigation, BI; tube-sprinkler irrigation, SI; pillow irrigation, PI and drip irrigation, DI) with various irrigation amount/frequency on yield, economic returns and water use efficiency (WUE) of winter wheat. Under the same limited irrigation amount (90 mm/season), two irrigation applications (45 mm/application) conducted using DI significantly increased the yield and WUE as compared with the BI using one single application. Increasing the seasonal irrigation amount to 160 mm, the increase in the application frequency by reducing the irrigation amount per application didn't significantly affect the yield using either PI or SI. Results showed that soil water depletion (SWD) contributed 40-60% of the seasonal evapotranspiration (ET) under limited water supply. The smaller root length density (RLD) in deep layers of the soil restricted the soil water uptake by the crop. Therefore, increasing irrigation frequency would maintain the top soil layers with higher soil water contents where RLD was greater that improved crop water use and yield under limited water supply. However, when irrigation water was plentiful, micro-irrigation methods did not increase yields. Due to the high cost in installation of the three micro-irrigation systems, their net income was reduced by 30% as compared with the BI method. The economic water productivity ratio (EWPR) was only 3-4 for the three micro-irrigation systems, much less than the basin irrigation method, which had an average value of 16. Currently, the basin irrigation method is more economic for growing winter wheat in the NCP.
Irrigation frequency is one of the most important factors in drip irrigation scheduling and production planning, where water resources are limited, that affects soil water regime, water and fertilization use efficiency and crop yield. Therefore, field experiments were conducted for 2 years in the summer season of 2011 and 2012 on sandy loam soil to investigate the effects of irrigation frequency under surface and subsurface drip irrigation systems on growth parameters, grain yield, N, P and K uptakes, and water use efficiency (WUE) of maize (Zea mays L.). The results indicated that the highest values of maize growth parameters were gained when irrigating plants with 100 % of the ETc (2500 m 3 /fed.= high frequency) treatment by using subsurface drip irrigation system. On the contrary, the lowest values appeared by irrigating plants by 1900 m 3 /fed. (70 % of ETc = low frequency) under surface drip irrigation system. There were no significant differences between the growth parameters values by using the two experimental irrigation systems, but the differences increased by using the different water quantities. The highest maize grain yield (2638 and 2575 kg/fed.) were gained by using control irrigation water quantity (2500 m 3 /fed.) comparing with the other two water quantities under subsurface and surface drip irrigation system, respectively. The significant differences were appeared for N, P and K uptakes values by the effect of water quantities, and the interaction between water quantities and irrigation systems, but there were no significance under the individual effect of irrigation systems. The relationship between water quantities and maize grain yield using drip irrigation system under semi arid conditions is 1 st degree.
International Journal of Plant & Soil Science
The aim of this research is to determine the appropriate irrigation scheduling under three different maize varieties in Northern Guinea Savanna agro ecological zone of Nigeria. The trial was conducted during the 2015 and 2016 dry seasons at the Institute for Agricultural Research (IAR) field in Samaru (Latitude 11.11° N and Longitude 7.38°E). The experiment was laid out as a splitplot design replicated three times. Planting dates and supplementary Irrigation levels were in the main plots while maize varieties formed the sub-plots with the planting dates at 10days interval starting from March and February respectively. Three levels of irrigation were imposed based on levels of cumulative pan evaporation (E pan) values of 1.0 E pan (EI 1), 0.70 E pan (EI 2) and 0.40 E pan (EI 3). Results from the two trials, revealed more efficient utilization of soil moisture by crops irrigated with 70 CU irrigation regime (6.91 and 6.97 kg grain/mm water respectively for the two Original Research Article
African Journal of Agricultural Research, 2015
This experiment was conducted during February to June 2012 in Demonstration farm of Arba Minch University located in the central rift valley of Ethiopia. The aim was to investigate the effects of different levels of deficit irrigation imposed at different growth stages of maize (BH-140) crop on its development, grain yield and water use efficiency. AquaCrop model was calibrated and validated using field experimentation data. The crop water requirement of maize for full irrigation application was calculated using CropWat 8.0. The water application levels considered were 100% of crop evapotranspiration (ETc), 75%ETc, 50%ETc and 25%ETc. based on these irrigation levels and four growth stages of maize crop, ten treatments were arranged. These treatments were replicated three times. Data collected during the experiment were: crop biomass, soil moisture content, irrigation depths and final yield. The result showed that the highest yield was found in treatment six, T6 (8842 Kg/ha) which was subjected to water deficit during mid-and maturity-stages; whereas minimum yield of about 5264 kg/ha was obtained under T8 which was irrigated imposed to deficit during the whole growing season except during the initial stage. The highest (2.11 kg/m 3) and lowest (0.93 kg/m 3) water use efficiency was recorded under T8 and T4. Generally, water deficit of 50%ETc during third and fourth growth stages had no significant effect on the grain yield of maize and it is worthwhile to save irrigation water during these growth stages. The model performed well in simulating the growth of aboveground biomass, grain yield, and canopy cover (CC) for most of the treatments but it was less satisfactory in simulating the growth performance of treatments under prolonged water-deficit. The fact that the AquaCrop model is easy to use, requires less input data, and its sufficient degree of simulation accuracy make it a valuable tool for estimating crop productivity under deficit irrigation, and on-farm water management for improving the efficiency of water use in agriculture.
A model for deficit irrigation analysis of crops
Progress in Agricultural Engineering Sciences, 2009
Scarcity and high cost of water is the most important limiting factor for crop production in irrigated agriculture. Deficit irrigation can be implemented to optimize the use of available water resources and put more land on productive use. A model was developed to determine the savings in water and the economic benefit derived from deficit irrigation. The model was tested using yield-water use data of maize, tomato, okra and cowpea grown under irrigated condition in Nigeria. Cowpea is the main source of plant protein in the local diet and okra one of the major vegetable crops planted in Nigeria. The results indicated that some water reduction is possible without affecting yields. The optimum water reduction is 4, 8, 12 and 18% for maize, tomato, okra and cowpea, respectively. Maximum allowable water reduction increased with increase in the benefitcost ratio of each tested crop. The maximum allowable water reduction is 9, 13, 21 and 32%, with a corresponding increase in cultivated area by 10, 16, 23 and 50% for maize, tomato, okra and cowpea, respectively, at a benefit-cost ratio of 1.5. The model, in most of the years showed that the optimum moisture reduction level increased with increasing seasonal rainfall. Increasing rooting depth or soil water holding capacity also increased the relative maximum yield for water reduction levels up to 40-50%. The developed model would be useful in determining the effect of soil, water, and crop variables on deficit irrigation of crops in different agro-ecological zones with appropriate crop and soil data input, and proper irrigation scheduling.
International Journal of Agricultural Economics
This study was aimed to compare estimation methods of crop water requirement and irrigation scheduling for major crops using different models and compare the significance of models for adoption at different situations in Metekel zone. Crop water requirement and irrigation scheduling of maize in selected districts of Metekel zone were estimated using CropWat model based on soil, crop and meteorological data and AquaCrop based on soil, crop and meteorological data including Co2, groundwater, field management, and fertility status. Model performance was evaluated using Normalized Root mean square errors (NRMSE), model by Nash-Sutcliffe efficiency (NSE), Prediction error (Pe), and Model efficiency (MF). It is observed that the maximum reference evapotranspiration in the study area was found to be 7.1 mm/day in Guba and minimum reference evapotranspiration was 2.9 mm/day in Bullen district. In all cases, the maximum ETo in all districts was fund to in March and the lowest in August. The maximum ETc of maize was found to be 702.4 mm in Guba district and minimum ETc was found to be 572.6 mm in Bullen district using CropWat but the effective rainfall (Pe) for maize were determined as 185 mm respectively in Wembera district. However, using AquaCrop model the maximum ETc of 565 mm was recorded in Guba but 425 mm was recorded as minimum in Wembera district for irrigated maize in the study area. The study revealed that the irrigation scheduling with a fixed interval criterion for maize 10 days with 12 irrigation events has been determined. Moreover, furrow irrigation with 60% irrigation application efficiency was adjusted during irrigation water applications for all districts. The performance of the irrigation schedule and crop response was evaluated by the analysis results in the simulation using different models. It has been observed that there was a strong relationship and a significant relation between the simulated and observed values for validation. Hence, Normalized Root mean square errors (NRMSE), model by Nash-Sutcliffe efficiency (NSE), Prediction error (Pe), and Model efficiency (MF) showed that AquaCrop model well simulated in all parameters considered. AquaCrop model is the most suitable soil-water-crop-environment management model, so future studies should suggest a focus on addressing deficit irrigation strategy with different field management conditions to improve agricultural water productivity under irrigated agriculture for the study area for major crops.
Effects of deficit irrigation scheduling on yields and soil water balance of irrigated maize
Irrigation Science, 2008
This paper presents the findings of the effect of some selected deficit irrigation scheduling practices on irrigated maize crop in a sub-catchment in south western part of Tanzania. Field experiments, in which maize (TMV1-ST) variety was planted under total irrigation, were conducted during the dry seasons of 2004 and 2005. Surface irrigation method was used and the crop was planted in basins. The seasonal water applied ranged from 400 to 750 mm. Soil moisture content from both cropped and bare soils, leaf area index, dry matter, and grain yields were measured. The dry matter yield ranged between 6,966 and 12,672 kg/ha, and grain yields obtained were between 1,625 and 4,349 kg/ha. The results showed that deficit irrigation at any crop growth stage of the maize crop led to decrease in dry matter and grain yields, seasonal evapotranspiration and deep percolation. Deficit irrigation in any one growth stage of the maize crop only seems to affect grain production and no significant effect on biomass production, but deficit irrigation that spanned across two or more growth stages affect both biomass and grain production drastically. Crop water use efficiency (WUE) and Irrigation water use efficiency (IWUE) were strongly influenced by the number of growth stages in which deficit irrigations were applied and how critical the growth stages were to moisture stress rather than the amount of irrigation water applied. While maximum WUE was obtained under full irrigation, maximum IWUE was obtained in the deficit irrigation treatment at vegetative growth stage, which suggest that IWUE may be improved upon by practicing deficit irrigation at the vegetative growth stage of the maize crop.