Residual Effects of Farm Yard Manure on Soil Properties in Spring Season, Chitwan, Nepal

Abstract

Farm Yard Manure (FYM) is major organic manure used in the context of Nepal. Year round availability of FYM is difficult because of decreasing livestock population. Two experiments were carried out in Randomized complete block design with six treatments (0, 7, 14, 21, 28, 35 tons FYM/ha) replicated four times at the research farm of IAAS, Rampur, Chitwan, Nepal. First experiment was conducted in winter season (Oct-Jan) and second experiment was conducted in spring season (Feb - May). No additional FYM was kept in second season in order to study the residual effect of farm yard manure. 50% of the FYM mineralized in the first season hence, for second season residual levels of FYM (0, 3.5, 7, 10.5, 14, 17.5 t/ha) were considered as treatments. In winter season Broccoli (Brassica oleracea var. italilca) and in spring season Mung beans (Vigna radiata) were planted. EC1:5 and pH were not significantly affected in winter season but pH significantly differs in spring season residuals. The highest pH value (6.9 ± 0.11) was observed in the residual FYM level 10.5 t/ha. EC1:5 in spring season also not significantly affected by residual FYM level. There is decreasing trend of bulk density and increasing trend of porosity was found. The highest porosity and the lowest bulk density values were obtained from the treatments 21 tons FYM/ha in first season and also from residual FYM level 10.5 t/ha. Crop yields and biomass production were also significantly different in 21 tons FYM/ha than rest of other treatments. Hence, 21 tons FYM/ha in dry matter basis is optimum dose of FYM in Chitwan context to maintain the soil and residual level is also sufficient to supply plant nutrients fertility in legume rotated system.