Soil Test Crop Response: Concepts and Components for Nutrient Use Efficiency Enhancement

Abstract

The economy of the country is based on agriculture where 70 % of the total population is in rural areas dependent in agriculture. Fertilizers are one of the costly inputs but continue to exert significant contribution to produce additional food grains for the ever-increasing population. The promotion of balanced chemical fertilizers has become a necessity to meet the ever-increasing demands of food grains, pulses, oil crops, sugarcane production, fruits, vegetables, fibres, forage and grasses. It has been proved that imbalance use of fertilizer not only causes deterioration in soil quality but also affected nutrient use efficiency. Soil forms the basis for any crop production activity and is the most precious natural resources. Declining soil fertility is one of the important factors that directly affect the productivity. Blanket crop production technologies including fertilizer recommendations have accelerated the situation over three to four decades. Therefore, soil fertility management is crucial to ensure productivity and nutritional security while maintaining soil health and sustainability. To get a maximum benefit, enhanced nutrient use efficiency and reduced nutrient losses from fertilizers, they must be applied in the right quantity, sources and combination at the right time using the right methods. The package of practices recommended should cater to the need of soil variability. The response to fertilizers is greatly influenced by the soil type and spatial soil variability that has resulted from complex geological and paedological processes. Spatial variation of soil properties decreases the use efficiency of fertilizers applied uniformly at the field scale. Therefore, application of variable rates of fertilizers has been proposed.