Sustainable soil management through fertigation for achieving high yield and quality produce

摘要

Micro irrigation, a technique that provides crops with water through a network of pipe lines at a high frequency but with a low volume of water (drips) applied directly to the root zone in a quantity that approaches consumptive use of the plants, canbe combined with fertilizer application, to offer fertigation. Fertigation enables the farmer to meet the specific water and nutrient needs of the crops with great precision, thus minimizing losses of both precious water and nutrients. The direct delivery of fertilizers through drip irrigation demands the use of soluble fertilizers and pumping and injection systems for introducing the fertilizers directly into the irrigation system. Fertigation allows an accurate and uniform application of nutrients tothe wetted area, where the active roots are concentrated. The nutrients are applied as per the crop need at different growth stages in split manner. The problem of mobility of non-mobile nutrients is also addressed using fertigation. Planning the irrigation system and nutrient supply to the crops according to their physiological stage of development, and consideration of the soil and climate characteristics, result in high yields and high quality crops with minimum pollution A beneficial side effect offertigation is the avoidance of soil erosion and soil degradation, in that it eliminates the use of heavy machinery that can cause soil compaction. In addition, less water is needed to produce unit weight of dry matter, since the water supply can be adapted to the speed of infiltration, thereby avoiding surface runoff and erosion. Fertigation allows cover crops or spontaneous vegetation to be grown in between rows of trees, with positive effects on soil conservation. Moreover, this technique facilitatesthe growing of trees on slopes, thereby making a further contribution to the prevention of erosion. In humid regions and areas with high rainfall, farmers work actively to maintain or improve the soil's ability to 'digest' water. In India about 4 Mha ofland have been brought under pressurized irrigation (sprinkler and micro irrigation). Most of the crops irrigated under micro irrigation are horticultural crops. However, field crops such as sugarcane, groundnut, cotton etc are also being brought undermicro irrigation. The fertilizer applications to these micro irrigated crops are partially through fertigation in pen field condition, However, most of the crops under polyhouse condition are under fertigation. In this paper efforts has been made to discuss various issues of fertigation including selection of water soluble and liquid fertilizers, fertilizer requirement and fertigation scheduling for improved fertilizer use efficiency, fertilizer saving, increased crop yield and quality produce in a sustainable manner.