Opportunities for water harvesting and supplemental irrigation for improving rainfed agriculture in semi-arid areas.

Abstract

This chapter discusses the research results and experiences gained in runoff harvesting and supplemental irrigation in the semiarid tropical (SAT) regions of India and Africa. Topics covered include: traditional tank irrigation in SAT India; assessment of adequate water availability in tanks at critical crop growth stages; optimum tank size and other design parameters; efficient application of supplemental irrigation water; crop responses to supplemental irrigation; economic evaluation of runoff storage structures and supplemental irrigation; and watershed-based water harvesting, groundwater recharging and efficient water utilization.

Soil Testing as a Tool for On-Farm Fertility Management: Experience from the Semi-arid Zone of India

“…It is recognized that water shortage related plant stress is the primary constraint to crop production and productivity in the rainfed systems in the SAT and consequently the importance of water shortage has globally been rightly emphasized (Wani et al 2002(Wani et al , 2003CAWMA 2007;Pathak et al 2009). However, apart from water shortage, there is the issue of severe soil infertility problems in the rainfed systems Sahrawat et al 2010b;Bekunda et al 2010) and managing water stress alone cannot sustainably enhance the productivity of rainfed systems; and hence for achieving sustainable gains in rainfed productivity both water shortage and soil fertility problems need to be simultaneously addressed through effective natural resource management practices Sahrawat et al 2010a).…”

Managing the Selenium Content in Soils in Semiarid Environments through the Recycling of Organic Matter

“…Sustainable crop production needs to maintain the soil fertility on a long-term basis, and it is essential that the organic matter and nutrients removed during harvest are replenished through external application on a regular basis. Some authors recommend the maintenance of the soil organic matter at a threshold level, which will depend on the soil and climatic factors, to ensure the physical, chemical, and biological integrity of soil to achieve sustainable agricultural and environmental functions [47][48][49][50][51].…”

Hydrological behavior of Alfisols and Vertisols in the semi-arid zone: Implications for soil and water management

“…Due to these, the current agricultural productivity on these soils in most SAT regions remains low . Also with the current land use system, the rainfall use efficiency of the production systems are low, ranging from 35-55%, thus annually a large percentage of annual rainfall is lost as surface runoff, evaporation and deep drainage (Pathak et al, 2009;Pathak et al, 1989). Groundwater levels are depleting fast, and most rural rainfed areas are facing general water scarcity (Rockstrom et al, 2007).…”

“…However, the stored runoff can be most effectively utilized as pre-sowing irrigation for post-rainy season crops. In the medium rainfall regions of Vertisols, excellent responses to pre-sowing irrigation have been recorded (Pathak et al, 2009). …”