Effect of fertigation on crop productivity and nutrient use efficiency

Abstract

Sustained higher yield with high yielding varieties depends entirely on the sustainable use of the limited water and energy resources, specifically in developing countries with arid and semi-arid regions. Moreover, intensification of agricultural production to meet growing market demand requires the simultaneous application of irrigation water and fertilizers. In other side deficiency of N, P and K is a major production constraint in sandy soils, which have inherent constraints like P fixation, rapid hydraulic conductivity, faster infiltration rate, leaching of basic cations and low CEC. Hence, the cultivated crop in this soil requires large quantity of nutrients to support its growth and yield. Considering the soil and crop constraints, fertilizers should be applied in synchrony with crop demand in smaller quantities during the growing season. The right combination of water and nutrients is a prerequisite for higher yields and good quality production. The method of fertilizer application is also important in improving the use efficiency of nutrients. A modern agro -technique which can solve the above issue is, Fertigation - a technique of application of fertilizers along with irrigation water, provides an excellent opportunity to maximize yield and minimize environmental pollution (Hagin et al. 2002). Fertigation ensures availability of fertilizer nutrients in the root zone in readily available form and therefore, minimize fertilizer application rate and increase fertilizer use efficiency. The associated increase in yield with minimum fertilizer application rate, increases return on the fertilizer invested. Fertigation resulted increased in crop yield by 20 to 30 % (Sandal et. al.). Fertigation enables adequate supplies of water and nutrients with precise timing and uniform distribution to meet the crop nutrient demand. Reported that fertigation applied N and P fertilizer increased wheat grain yield by 16% over top dressed N (Vishandas et al. 2006). Fertigation allows the landscape to absorb up to 90% of the applied nutrients, while granular or dry fertilizer application typically result in absorption rates of 10 to 40%. Fertigation ensures saving in fertilizer (40-60%), due to “better fertilizer use efficiency” and “reduction in leaching” (Kumar et al. 2002).