Productivity and profitability of rice (Oryza sativa) as influenced by high fertility levels and their residual effect on wheat (Triticum aestivum)

Field experiments were conducted during Kharif and Rabi seasons for two consecutive years during 2008-09 and 2009-10 at Chaudhary Chhotu Ram Post-Graduate College, Muzaffarnagar, Uttar Pradesh to evaluate the direct and carryover effect of high fertility on productivity, profitability and soil nutrient status of rice (Oryza sativa L.) and wheat [Triticum aestivum (L.) emond. Fiori & Paol] under system approach. Fitteen fertility treatments comprised of N₁₀₀P₁₀₀K₁₇SZn₆₀, N₁₂₅P₁₀₀K₁₇₅Zn₆₀, N ₁₅₀P₁₀₀K₁₇₅Zn₆₀, N ₁₇₅P₁₀₀K₁₇₅Zn₆₀, N ²⁰⁰P₁₀₀K₁₇₅Zn₆₀, N ₂₂₅P₁₀₀K₁₇₅Zn₆₀, N ₂₂₅P₅₅K₁₇₅Zn₆₀, N ₂₂₅P₅₀K₁₇₅Zn₆₀. N ₂₂₅P₇₅K₁₇₅Zn₆₀, N ₂₂₅P₁₀₀K₁₂₅Zn₆₀, N ₂₂₅P₁₀₀K₁₂₅Zn₆₀, N ₂₂₅P₁₀₀K₁₅₀Zn₆₀. N ₂₂₅P₁₀₀K₁₇₅Zn₂₀. N ₂₂₅P₁₀₀K₁₇₅Zn₄₀ and N ₁₅₀P₆₀K₄₀Zn₂₀ (recommended dose ot fertilizer, RDF) were examined in Randomized Block Design replicated thrice. Treatment N₁₇₅P₁₀₀K₁₇₅Zn₆₀ produced the highest number of effective shoots, harvest index and grain yield ot rice to the tune of 6.99 tlha being 27.56% higher than RDF. Grain yield of rice started declining by the application of nitrogen over 175 kg/ha at constant and varied levels ot P, K and Zn. The response ot P was significant only at their highest level of 100 kg/ha while, the levels of K and ZnSO, did not have any distinguish effect on rice. Wheat crop grown under the residual fertility levels of highest rice yielding treatment recorded 2.16 tlha grain yield which was 19.8% lowered than the treatment N₂₂₅P₁₀₀K₁₇₅Zn₆₀. The total productivity and chemical energy generated by the system was the highest (9.67 t/ha, 139.7 × 10³ MJ/ha, respectively) under treatment N₁₇₅P₁₀₀K₁₇₅Zn₆₀ with the highest production elticiency of 71.11 kg/ha/day, The higher net monetary return (67,026/ ha) as well as B:C ratio (2.13) of the system was also witnessed under this treatment. The residual fertility status of soil atter rice harvest was higher under the application of N₂₂₅P₇₅K ₁₇₅Zn₆₀ to rice in rice-wheat cropping system.