How to tackle with water crisis in agriculture?

For optimum production of crops sufficient amount of good quality water is required but, there is a severe shortage of water in Pakistan. So for sustainable production of crops scientists are trying to explore new techniques to combat this situation. Furrow-bed method of irrigation saves considerable quantity of water and permits more efficient use as compared to other surface irrigation systems. Application of irrigation water in furrows gave higher leaf area index (LAI), net assimilation rate (NAR), crop growth rate (CGR), and grain yield of maize than alternate or paired skip furrow irrigation. Irrigation by flooding water over the entire field results in leaching down the nitrates from the root zone causing loss of fertilizer. Over irrigation often leads to greater leaching loss of fertilizer and thereby reduces the final plant height, dry matter accumulation and grain yield of maize. Under the growing water scarce situation and decreasing crop productivities, there is a need to develop and evaluate improved planting methods with higher water use efficiencies and provide more water for crop production. Some early work in Pakistan on non-permanent beds and furrow irrigation produced yield increases of 20 % for wheat, and 48 % for cotton.
Pakistan is an agricultural country with the world’s largest contiguous irrigation system, the Indus basin irrigation system (IBIS). In IBIS, field crops are irrigated using the basin irrigation method. Application losses in fields are around 25-40% under flood and basin irrigation. Low application efficiencies reported in IBIS result from over irrigation, improper irrigation methods and timings, non-scientific irrigation scheduling and non leveled fields.
Per capita water availability in Pakistan has been decreasing at an alarming rate due to increase in population that puts Pakistan in the category of ‘high stress’ countries in terms of limited water resources. In 1951, per capita availability was 5300 cubic meters, which has now decreased to 1090 cubic meter just touching water scarcity level of 1000 cubic meter. Due to growing population pressures and extended periods of drought, it has been estimated that an additional 48 billion m3 water would be required to meet the growing demands of agriculture and the country’s economy by the year 2011 (Pakistan Economic Survey, 2009). Now a days, water shortage shifts attention from the traditional concept of crop yield-production per unit of land-to the productivity of water-production per unit of water. Whether this parameter is best increased through responsive, sophisticated irrigation scheduling or through predetermined schedules, providing limited water, has been a contentious issue for some years.
Mulching is one of the techniques to improve soil quality by increasing soil organic carbon. It decreases the evaporation rate, leaving greater moisture and there is less variation in soil temperature for a longer period of time. Appropriate soil moisture and temperature are important for metabolic activity of the soil microbes that recycle and release nutrients that are essential for growth. Besides moderating soil moisture and temperature, mulch residue affects the dynamics of soil organic matter (SOM).
Sustainable increases in agricultural productivity are necessary to secure food availability and livelihoods in the developing world over the coming decades. Such increases must come largely through better use of the water and land by adopting new techniques.