Effect of nutrient management strategies on nutrients dynamics under long term fertilizer experiment with rice-wheat cropping system on a mollisol
Loading...
Date
2017-07
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
G.B. Pant University of Agriculture and Technology, Pantnagar - 263145 (Uttarakhand)
Abstract
A field experiment was conducted to study the effect of fertilizers on chemical fractions of nitrogen, phosphorus and potassium in Mollisol at G.B. Pant University Pantnagar during 2013-14 and 2014-15. Observed results showed that application of 100% NPK+FYM gave highest yield of rice (51.87 and 51.13 q ha-1) and wheat (49.73 and 48.63 q ha-1) during 2013-14 and 2014-15, respectively, which was significantly higher than all other fertilizer treatments. In surface soil nutrients status was higher in comparison to sub-surface soil depths. Nitrogen, phosphorus and potassium uptake by grain and straw of rice and wheat under different treatments showed significant results. Treatments 100%NPK+FYM produced highest N, P and K uptake by grain and straw and it was followed by treatment 100% NPK + Zn in both years. The lowest uptake by grain and straw of both crops was recorded in control for both the years of experimentation. A declining trends in soil organic carbon due to continuous use of fertilizers and cropping was recorded and very minute change in pH and electrical conductivity was observed. Total N in soil under all fertilizer treatments ranged from 567 to 915 mg kg-1 during 2013-14 and 563 to 932 mg kg-1 during 2014-15, respectively. Fractions of nitrogen in surface soil (0-15cm) ranged from 15.90 to 27.18, 7.00 to 18.10, 477 to 689 and 24.12 to 76.66 mg kg-1 of ammonical-N, nitrate-N, total hydrolysable-N and amino sugar-N, respectively in both years. Phosphorus fractions (available P, Ca-P, Al-P, Fe-P, Saloid P and total P) and K fractions (available K, water soluble K, exchangeable K, non-exchangeable K and total K) showed almost similar results as observed with N fractions under different fertilizer treatments in both crops at all depths of soils.
The continuous use of 100% NPK along with FYM in rice-wheat cropping system significantly improved the soil properties, nutrient status and crops yields. The nutrients (N, P and K) uptake by rice and wheat were highest under 100% NPK+FYM (T8) treatment in both kharif and rabi season during 2013-14 and 2014-15, respectively and thus it showed beneficial effect on soil fertility and yield and crop yields. Balanced use of fertilizers as 100% NPK + Zn showed higher crop yields, nutrients uptake and nutrients movement in soil as compared to 100%N+Zn and 50% NPK treatments. Significantly higher values of N, P and K fractions were found in top soils as compared to lower depths soils. Among the N, P and K fractions, NH4-N, NO3-N, Ca-P, Al-P, Exchangeable-K, soluble K were highly correlated to affect crop yields and nutrients uptakes by rice and wheat crops.