Mulching techniques: An approach for offsetting soil moisture deficit and enhancing manure mineralization during maize cultivation

摘要

Mulching is an effective technique for soil moisture conservation and increasing mineralization. Four mulching practices (i.e. no-mulch, canola residue, transparent and blue plastic) and five nitrogen (N) treatments (i.e. no-N, 100, 70, 50, 0 % from farmyard manure (FYM) with remaining from urea) to supply a total of 250 kg N ha(-1) were assessed under field and lab conditions for soil moisture conservation and quantification of soil organic matter (SOM), total nitrogen (TN) and mineral nitrogen (min-N) contents in 2013-14. A total of 40 % added water to the soil was lost in no-mulching compared to 7 % been lost in plastic mulching during first week in open shed. Based on moisture losses, three moisture regimes were developed and used in a 56 days incubation experiment. The 60 % relative water holding capacity (RWHC) corresponding to plastic mulching had lowered SOM (1.0 %), and TN (1.6 %) but increased min-N (5.9%) than 40% RWHC (corresponding to no-mulch). Among the nitrogen treatments, 100% FYM had improved SOM and TN, but mineralization was higher in 50% FYM/ urea. In field studies, the canola residue mulching had increased the SOM (8.4%), TN (1.2%), min-N (5.2%) and moisture contents (5.7%) over no-mulching. The 100% FYM had higher SOM (2.25 folds), TN (2.79 folds) and moisture content (11.3%) than control. In conclusion, soil fertility was improved with 100% FYM and mineral N with 50% FYM/urea. Thus, 100% FYM or 50 %FYM + 50 % urea sources to provide 250 kg N ha(-1) should be used with plastic mulching in weed infested area or residue mulch in weeds free field conditions for improving mineralization and water conservation.