Irrigation and Drainage最新文献

This research investigated soybean soil water dynamics under different irrigation levels in three different soil types in the same field concurrently. Treatments imposed in each soil type were: (i) variable-rate irrigation (VRI), (ii) fixed-rate full irrigation (FRI-1″ or FRI-25.4 mm) and (iii) fixed-rate limited irrigation (FRI-0.75″ or FRI-19 mm). In 2018, VRI received 75% less water than FRI-1″ and received 49% less water than FRI-0.75″. In 2019, VRI received 100% more irrigation than FRI-1″ and 41% less than FRI-0.75″. Soil water dynamics of each treatment in the same soil and between the soils exhibited substantial interannual variations. Soil type had substantial and greater impact on soil moisture dynamics than irrigation treatments. Total available water (TAW), dry spell and antecedent soil moisture were impacted to a greater extent by the spatial soil properties than irrigation treatments. The range of field capacity (FC), permanent wilting point (PWP), TAW, dry spell soil moisture and antecedent soil moisture quantified for each soil type spatially and temporally in the same research field with respect to soil moisture dynamics and impacts on irrigation requirements for different irrigation management strategies provide a beneficial scope of understanding the effects of these spatially variable soil properties on water management. The research also provides substantial evidence in terms of the critical importance of detailed quantification, analyses and understanding of the soil properties that must be considered for successful implementation of VRI technology.

Soybean growth, yield, crop evapotranspiration (ETc) and crop water use efficiency (CWUE or crop water productivity, CWP) under different irrigation levels in three different soil types in the same field were investigated concurrently. Treatments in each soil type were: (i) variable rate irrigation (VRI), (ii) fixed rate full irrigation (FR-1″) and (iii) fixed rate limited irrigation (FR-0.75″). There was not enough evidence suggesting the superiority of VRI over FRI-1″ or FRI-0.75″ in terms of improving yield or CWUE. Leaf area index (LAI) and plant height were stronger functions of soil types than irrigation treatments. Growing season cumulative grass-reference evapotranspiration (ETo) and cumulative precipitation were 629 and 489 mm, respectively, in 2018; and 589 and 551 mm, respectively, in 2019. Variations in yield among irrigation treatments for both seasons were not significant (p > 0.05). Soil type, rather than irrigation treatments, explained variation in yield with statistical significance (p < 0.05). Soil types had substantial impact on ETc and CWUE. Since spatial variability in soil properties has a profound impact on soybean growth, yield, ETc and CWUE, soil variability in horizontal and vertical domain must be considered for developing accurate management zones and prescriptions for VRI, and for in-season VRI, FRI and limited irrigation management for successful and effective operations.

Agricultural drainage plays a crucial role in land management and crop productivity but significantly impacts greenhouse gas (GHG) emissions. This study examines the effects of drained and undrained soil conditions on GHG emissions in croplands via a case study in Lincolnshire, United Kingdom. The ECOSSE (Estimating Carbon in Organic Soils – Sequestration and Emissions) model was employed to simulate carbon and nitrogen fluxes under varying water table depths and management scenarios. The results indicate that drained soils exhibit lower methane (CH₄) emissions due to increased aeration but higher carbon dioxide (CO₂) and nitrous oxide (N₂O) emissions due to enhanced microbial activity and organic matter decomposition. Conversely, undrained soils show reduced CO₂ and N₂O emissions but significantly higher CH₄ emissions under anaerobic conditions. Seasonal variations were evident, with peak emissions occurring in late spring and early summer. These findings emphasize the need for balanced drainage strategies, such as controlled water table management, to mitigate GHG emissions while maintaining agricultural productivity. This study provides valuable insights for policymakers and land managers seeking sustainable land-use practices that align with climate change mitigation goals.

Irrigation is a crucial practice for the security of rural businesses, ensuring agricultural production even in periods without rainfall. This work aimed to analyse the financial viability of an off-grid photovoltaic (PV) system as an alternative to traditional energy sources for pumping irrigation in Brazilian agricultural areas. The sources of photovoltaic solar energy and diesel were compared in terms of their supply of energy to drip irrigation systems designed for various perennial agricultural crops. The use of a decision tree approach enabled the prediction of the viability of the studied options. Among the analysed crops, banana had the highest viability for the use of photovoltaic systems. In the case without carbon sales, in 76% of the unrestricted area, the banana crop was economically more attractive, whereas this value was only 41% for the orange area. In terms of carbon sales, these values were 91% and 68%, considerably increasing the area with potential use of the photovoltaic system. A classification system using decision trees was created. The results obtained indicate that the off-grid system is viable for a large part of the national territory and that the percentage of viable areas increases notably when the sale of carbon credits is considered.

Irrigation development can be an effective economic force for agricultural production, regional development and urban and rural community development. This study estimated the societal economic footprint of the Irrigation Districts on the economy in Alberta, Canada, via a variety of economic impact analysis models. The analysis indicates that producers, agricultural and non-agricultural industries and communities benefit (either directly or indirectly) from irrigation development and related activities. These impacts result from the direct use of irrigation water for crop and livestock production, whereas other impacts are related to irrigation infrastructure (reservoirs and canals) that provides water for municipalities, food processing industries, recreation and wildlife habitat development. Irrigation Districts' direct annual contribution to Alberta's agri-food gross domestic product (GDP), a traditional measure of economic growth, was about $1 billion. This contribution increased, through indirect and induced impacts, to $5.4 billion for the provincial GDP—about 5 times greater than the direct contribution. About 81% of the GDP generated by the Irrigation Districts accrued to the province, and about 19% to the irrigation producers. This study revealed that irrigation development is a beneficial economic strategy for the province, irrigation producers, food processing industries and sustainable community development. This study also demonstrated that economically successful irrigation projects should develop linkages between irrigation producers and regional food processing industries.