Impact of Nutrient Management Practices on Exchangeable K, Ca, Mg, CEC and Correlations with Soil Properties Under Maize-wheat Cropping System

Abstract

In order to study the impact of nutrient management practices on exchangeable K, Ca, Mg, CEC and its correlations with soil properties in two depths (0-15 cm and 16-30 cm) under maize-wheat cropping system, a long term experiment was conducted at farm research centre of department of soil science falling under the jurisdiction of Birsa Agricultural University. The experiment consisted of nine treatments replicated thrice in a randomized block design were selected for the study. The selected treatments were T1-control, T2-100% N only where 100% N was applied through Urea fertilizers,T3- FYM where 100% N was supplied through FYM (full dose 22 t/ha), T4-100% NP here 110 and 90 kg ha-1were supplied through Urea and SSP fertilizers, respectively, T5-100% NPK here 110:90:70 kg ha-1 were supplied through Urea: SSP: MOP fertilizers, T6- ½ (N+FYM)+P (A-X/2)+K (B-Y/2) (INM) where 50% of the nutrient need was supplied through Urea, SSP & MOP fertilizer and the rest 50% need through FYM and T7-100% NPK + Lime where NPK applied through Urea, SSP & MOP fertilizer along with lime application in LR once in 4 years, T8-Lime+ FYM+ P (A-X)+K (B-Y), the 100% N need of the crop was met by application of FYM whereas the P & K need was met by the application of SSP & MOP fertilizer, T9-Lime+N the 100% N dose was supplied through Urea along with lime. The results indicated that exchangeable K was found to be significantly highest in T8 than rest of the treatments followed by T7 and T5 while lowest was in T4 treatment in both depths respectively. The exchangeable Ca2+ was found to be highest in treatment T7 followed by T8 and T3 than rest of the other treated plot while lowest amount was found in T2 in both the depths. The trend of exchangeable magnesium was found to be significantly different in 0-15 cm and 15-30 cm soil depths as the highest amount was observed in treatments such as T8 followed by T3 and T6 in surface depths (0-15 cm) while in sub-surface depths (15-30 cm) the highest amount was found in treatments T3 followed by T8 and T6 while the lowest amount was found in T2 treated plot in both depths. Cation exchangeable capacity (CEC) is one the vital soil parameters concerning to soil fertility measured in terms of c mol (p+) kg-1 of soil and it is significantly varied in surface soils as well as in sub-surface soil depths. The CEC was significantly higher in FYM treated plot as compared to Non-FYM treated plot. Therefore, the highest CEC was recorded in T3 treated plot than rest of the other treatment while the lowest one was recorded in T2 plot in surface soils as well as sub-surface soils. The correlation coefficient (r) values worked out among the various soil parameters at these depth of soil where pH was significantly and positively correlated with exchangeable Ca2+ and exchangeable Mg2+. Similarly organic carbon shows positive correlation with exchangeable Mg2+ and exchangeable K+. Whereas EC and CEC shows non-significant but positive correlation with the parameters taken under study. The result of the present study will be highly useful for improving the soil fertility by using suitable and judicious combination of nutrient management with various cropping system side by side and hence provides a scientific scope for further research work.