Development of soil test crop response based fertilizer prescriptions through integrated plant nutrition system for aggregatum onion (Allium cepa L.) under drip fertigation.

An insight into the balanced crop nutrition and efficient irrigation will be rewarding to attain profitable bulb yield of shallow-rooted and high nutrient requiring aggregatum onion. To develop fertilizer prescription equations(FPEs) for aggregatum onion under drip fertigation by encompassing the Soil Test Crop Response approach (STCR), a field experiment was conducted in Palaviduthi soil series with 15 treatments viz., Absolute control (T₁), Blanket recommendation (60:60:30) + Farm Yard Manure (FYM) @ 12.5 t ha^-1(T₂), STCR based NPK fertilizer recommendation (STCR-NPK) for the targeted yield of 14 (T₃),15 (T₄),16 t ha^-1 (T₅), FYM @ 6.25 (T₆), 12.5 t ha^-1 (T₇), STCR-NPK+FYM @ 12.5 t ha^-1 for the targeted yield of 14 (T₈),15 (T₉),16 t ha^-1 (T₁₀), Biocompost @ 2.5 (T₁₁), 5 t ha^-1 (T₁₂) and STCR-NPK+Biocompost @ 5 t ha^-1 for the targeted yield of 14 (T₁₃),15 (T₁₄),16 t ha^-1 (T₁₅). The results revealed that T₁₀ was more supercilious than others. The basic parameters were deliberated from the experimental data on total nutrient uptake, initial soil fertility status, applied fertilizer doses. The aggregatum onion (variety CO 4) required 0.43, 0.32, 0.45 Kg of N, P₂O₅, K₂O to produce one quintal of bulb yield. The percent contribution of nutrients from soil and fertilizer was 14.01, 54.57 for N, 35.11,50.50 for P₂O₅ and 12.69, 70.12 for K₂O, respectively. The contribution of N, P₂O₅, K₂O from FYM and biocompost were 41.02, 16.23, 41.53 and 47.98, 15.87, 49.56 percent sequentially. Based on the above parameters, the fertilizer prescription equations were formulated for aggregatum onion under drip fertigation in Palaviduthi soil series. [ABSTRACT FROM AUTHOR]