EFFECT OF POTASSIUM HUMATE APPLICTION AND IRRIGATION WATER LEVELS ON MAIZE YIELD, CROP WATER PRODUCTIVITY AND SOME SOIL PROPERTIES

SUMMARYThe present study concerns identification of the most profitable and water and nitrogen use efficient best management practice (BMP) in a rice–wheat system using a combined approach of field experimentation and simulation. In the field study, two independent experiments, (1) effect of three transplanting/sowing dates, two cultivars and two irrigation regimes and (2) effect of four nitrogen (N) levels with four irrigation regimes, were conducted for two seasons of 2008–09 and 2009–10 at Punjab Agricultural University, Ludhiana, India. Integrating the treatments of the two independent field experiments, simulations were run with the CropSyst model. The BMP demonstrated was transplanting of rice on 20 June and sowing of wheat on 5 November, irrigation to rice at 4-day drainage period and to wheat at irrigation water depth/Pan–E (open pan evaporation) ratio of 0.9, and fertilizer N of 150 kg ha−1 to each crop for medium-duration varieties. This practice gave higher profit (35%), equivalent rice yield (16%), crop water productivity (15%), irrigation water productivity (51%), economic water productivity (34%) and economic N productivity (94%) than the existing practice by the farmers. The improvement in crop water productivity by shifting the transplanting/sowing date was due to reduction in soil water evaporation and increased transpiration and fertilizer N productivity through increased N uptake.

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Water availability, demand and reliability of in situ water harvesting in smallholder rain-fed agriculture in the Thukela River Basin, South Africa

Hydrology and Earth System Sciences ◽

10.5194/hess-13-2329-2009 ◽

2009 ◽

Vol 13 (12) ◽

pp. 2329-2347 ◽

Cited By ~ 18

Author(s):

J. C. M. Andersson ◽

A. J. B. Zehnder ◽

G. P. W. Jewitt ◽

H. Yang

Keyword(s):

River Basin ◽

Water Availability ◽

Water Productivity ◽

Maize Yield ◽

Coefficient Of Determination ◽

Water Harvesting ◽

Crop Water ◽

Crop Water Productivity ◽

Uncertainty Band

Abstract. Water productivity in smallholder rain-fed agriculture is of key interest for improved food and livelihood security. A frequently advocated approach to enhance water productivity is to adopt water harvesting and conservation technologies (WH). This study estimates water availability for potential in situ WH, and supplemental water demand (SWD) in smallholder agriculture in South Africa's Thukela River Basin (29 000 km2, mean annual precipitation 550–2000 mm yr−1). The study includes process dynamics governing runoff generation and crop water demands, quantification of prediction uncertainty, and an analysis of the reliability of in situ WH. The agro-hydrological model SWAT (Soil and Water Assessment Tool) was calibrated and evaluated with the Sequential Uncertainty Fitting algorithm against observed discharge (at ten stations) and maize yield (the dominant crop type) for the period 1997–2006. The water availability was based on the generated surface runoff in smallholder areas. The SWD was derived from a scenario where crop water deficits were met from an unlimited external water source. The reliability was calculated as the percentage of years in which water availability ≥SWD. This reflects the risks of failure induced by the temporal variability in the water availability and the SWD. The calibration reduced the predictive uncertainty and resulted in a satisfactory model performance. For smallholder maize yield, the Root Mean Squared Error was 0.02 t ha−1 during both the calibration and the evaluation periods. The width of the uncertainty band was reduced by 23% due to the calibration. For discharge during the calibration (evaluation) period, the ten-station range in the weighted coefficient of determination (Φ) was 0.16–0.85 (0.18–0.73), and in the coefficient of determination (R2) 0.42–0.83 (0.28–0.72). The calibration reduced the width of the uncertainty band by 25% on average. The results show that the smallholder crop water productivity is currently low in the basin (spatiotemporal median: 0.08–0.22 kg m−3, 95% prediction uncertainty band (95PPU)). Water is available for in situ WH (spatiotemporal median: 0–17 mm year−1, 95PPU) which may aid in enhancing the crop water productivity by meeting some of the SWD (spatiotemporal median: 0–113 mm year−1, 95PPU). However, the reliability of in situ WH is highly location specific and overall rather low. Of the 1850 km2 of smallholder lands, 20–28% display a reliability ≥25%, 13–16% a reliability ≥50%, and 4–5% a reliability ≥75% (95PPU). This suggests that the risk of failure of in situ WH is relatively high in many areas of the basin.

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Forty Years of Increasing Cotton’s Water Productivity and Why the Trend Will Continue

Applied Engineering in Agriculture ◽

10.13031/aea.13911 ◽

2020 ◽

Vol 36 (4) ◽

pp. 457-478

Author(s):

Edward M Barnes ◽

B. Todd Campbell ◽

George Vellidis ◽

Wesley Porter ◽

Jose Payero ◽

...

Keyword(s):

United States ◽

Water Use ◽

Irrigation Water ◽

Water Productivity ◽

The United States ◽

Irrigation Scheduling ◽

Crop Water ◽

Water Requirements ◽

Crop Water Productivity ◽

The U.S

Highlights Over the last 40 years the amount of irrigation water used by cotton in the United States has decreased while yields have increased leading to a large increase in crop water productivity (CWP). Many factors have contributed to improved CWP, such as improvements in water delivery systems. Irrigation scheduling technologies have also contributed to improved CWP; however, farmer adoption of advanced scheduling technologies is still limited and there is significant room for improvement. Increased yields from improved cultivars without an increase in water requirements has also been important for CWP. Continued developments in sensor technologies and improved crop simulation models are two examples of future strategies that should allow the U.S. cotton industry to continue an upward trend in CWP. Abstract. Over the last 40 years the amount of irrigation water used by cotton in the United States has decreased while yields have increased. Factors contributing to higher water productivity and decreased irrigation water use include migration of cotton out of the far western U.S. states to the east where more water requirements are met by rainfall; improved irrigation delivery systems with considerable variation in types and adoption rates across the U.S.; improved irrigation scheduling tools; improved genetics and knowledge of cotton physiology, and improved crop models that can help evaluate new irrigation strategies rapidly and inexpensively. The considerable progress over the last 40 years along with the promise of emerging technologies suggest that this progress will continue. Keywords: Cotton, Crop water productivity, Irrigation, Sustainability, Water use efficiency.

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Assessing crop yield and crop water productivity and optimizing irrigation scheduling of winter wheat in the Haihe plain using hydrological model

10.5194/egusphere-egu2020-6505 ◽

2020 ◽

Author(s):

Chen Sun ◽

Xu Xu

Keyword(s):

Winter Wheat ◽

Crop Yield ◽

Irrigation Water ◽

Water Productivity ◽

Swat Model ◽

Irrigation Scheduling ◽

Crop Water ◽

Potential Yield ◽

Irrigation Amount ◽

Crop Water Productivity

Haihe plain is an important food production area in China, facing an increasing water shortage. The water used for agriculture accounts for about 70% of total water resources. Thus, it is critical to optimize the irrigation scheduling for saving water and increasing crop water productivity (CWP). This study firstly simulated crop yield and CWP for winter wheat in historical scenario during 1961-2005 for Haihe plain using previously well-established SWAT model. Then scenarios under historical irrigation (scenario 1) and sufficient irrigation (scenario 2) were respectively simulated both with sufficient fertilizer. The crop yield in scenario 2 was considered as the potential crop yield. The optimal irrigation scheduling with sufficient fertilizer (scenario 3) was explored by iteratively adjusting irrigation scheduling based on the scenario 1 and previous studies related to water stress on crop growth. Results showed that net irrigation amount was reduced 23.1% in scenario 3 for winter wheat when compared with scenario 1. The CWP was 12.1% higher with very slight change of crop yield. Using optimal irrigation scheduling could save 8.8&#215;108 m3 irrigation water and reduce about 16.3% groundwater over-exploitation in winter wheat growth period. The corresponding yield was 18.5% less than potential yield for winter wheat but using less irrigation water. Therefore, it could be considered that the optimal irrigation was reasonable, which provided beneficial suggestions for increasing efficiency of agricultural water use with sustainable crop yield in Haihe plain.

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Irrigation Management Effects on Crop Water Productivity for Maize Production in the Texas High Plains

Water Conservation Science and Engineering ◽

10.1007/s41101-020-00100-x ◽

2021 ◽

Vol 6 (1) ◽

pp. 37-43

Author(s):

Gary W. Marek ◽

Thomas H. Marek ◽

Steven R. Evett ◽

Yong Chen ◽

Kevin R. Heflin ◽

...

Keyword(s):

Water Productivity ◽

Irrigation Management ◽

High Plains ◽

Crop Water ◽

Maize Production ◽

Crop Water Productivity ◽

Texas High Plains ◽

Management Effects

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Simulated efficient growth-stage-based deficit irrigation strategies for maximizing cotton yield, crop water productivity and net returns

Agricultural Water Management ◽

10.1016/j.agwat.2021.106840 ◽

2021 ◽

Vol 250 ◽

pp. 106840

Author(s):

Sushil Kumar Himanshu ◽

Yubing Fan ◽

Srinivasulu Ale ◽

James Bordovsky

Keyword(s):

Deficit Irrigation ◽

Growth Stage ◽

Water Productivity ◽

Cotton Yield ◽

Crop Water ◽

Net Returns ◽

Crop Water Productivity

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Maize Seedling Establishment, Grain Yield and Crop Water Productivity Response to Seed Priming and Irrigation Management in a Mediterranean Arid Environment

Agronomy ◽

10.3390/agronomy11040756 ◽

2021 ◽

Vol 11 (4) ◽

pp. 756

Author(s):

AbdAllah M. El-Sanatawy ◽

Ahmed S. M. El-Kholy ◽

Mohamed M. A. Ali ◽

Mohamed F. Awad ◽

Elsayed Mansour

Keyword(s):

Grain Yield ◽

Deficit Irrigation ◽

Water Productivity ◽

Irrigation Management ◽

Seed Priming ◽

Severe Drought ◽

Arid Environments ◽

Crop Water ◽

Crop Water Productivity ◽

Irrigation Regimes

Water shortage is a major environmental stress that destructively impacts maize production, particularly in arid regions. Therefore, improving irrigation management and increasing productivity per unit of water applied are needed, especially under the rising temperature and precipitation fluctuations induced by climate change. Laboratory and field trials were carried out in the present study, which were aimed at assessing the possibility of promoting maize germination, growth, grain yield and crop water productivity (CWP) using seed priming under different irrigation regimes. Two seed priming treatments, i.e., hydro-priming and hardening versus unprimed seeds, were applied under four irrigation regimes, i.e., 120, 100, 80 and 60% of estimated crop evapotranspiration (ETc). The obtained results indicated that increasing irrigation water from 100% up to 120% ETc did not significantly increase grain yield or contributing traits, while it decreased CWP. Deficit irrigation of 80 and 60% ETc gradually decreased grain yield and all attributed traits. Seed priming significantly ameliorated seedlings’ vigor as indicated by earlier germination, higher germination percentage, longer roots and shoots, and heavier fresh and dry weight than unprimed seeds with the superiority of hardening treatment. Additionally, under field conditions, seed priming significantly increased grain yield, yield contributing traits and CWP compared with unprimed treatment. Interestingly, the results reflect the role of seed priming, particularly hardening, in mitigating negative impacts of drought stress and enhancing maize growth, grain yield and attributed traits as well as CWP under deficit irrigation conditions. This was demonstrated by a significant increase in grain yield and CWP under moderate drought and severe drought conditions compared with unprimed treatment. These results highlight that efficient irrigation management and seed priming can increase maize yield and water productivity in arid environments.

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