Long Term Impact of Tillage Systems, Irrigation and Nitrogen on Soil Properties, Growth, Yield, Nutrient Uptake and Quality of Wheat (Triticum Aestivum L.)

A field experiment was carried out consecutively for five years (2011-12 to 2015-16), in split-split plot design with three replications, to elucidate the long term impact of irrigation and nitrogen levels on soil physico-chemical properties, growth, yield and quality under different tillage systems in wheat. Long term zero tillage + mulch resulted significant reduction of bulk density from 1.37 Mg/m3 to 1.33 Mg/m3 at o-15 cm depth and a favorable shift in pH from an initial 7.74 to 7.45. Plants raised under zero tillage + mulch grew 6.75 percent tall and maintained 3.8 percent more shoots over conventional tillage, had 10.61, 7.52 and 12.84 percent higher biological, grain and straw yield, respectively over zero tillage. Similarly zero tillage + mulch resulted 15.58 and 14.29 % higher Fe uptake over conventional tillage, and resulted 5146 and 2850 higher net return over zero tillage and conventional tillage, respectively. Plants enjoying seven irrigations had 6.0 percent higher dry matter as compared to four irrigations. Whereas, maximum grain yield (6.05 t/ha) was observed with six irrigations. Six irrigations had 8.0 percent higher grain yield over four irrigations and resulted 9.01, 9.63, 8.12, 13.04 and 40.66 percent higher uptake of N, P, K, S and Fe over four irrigations, respectively. At 90 DAS, plants fertilized with 180 kg N/ha, retained 26.09 percent higher leaves, and maintained 2.27 percent higher total chlorophyll over 120 kg N/ha. Biological (15.27 t/ha) and straw yields (9.74 t /ha) were significantly higher with 180 kg N/ha. However maximum grain yield (5.99 t/ha) and harvest index (0.39) observed under 150 kg N/ha. The protein content was highest with 180 kg N/ha (12.33 %), whereas, starch content, could not cross the level of significance. Nitrogen application @ 150 kg N /ha resulted an additional return of 8983 over 120 kg N.