Effect of Long-Term Fertilization and Hybrid Maize on Seasonal and Temporal Changes in Soil Enzyme Activity

Soil enzymes play vital role in nutrient mineralization and their activity in soil is an excellent sensor in predicting the nutrient supplying capacity to plants. A field experiment was conducted to study the effect of long-term fertilization and maize hybrid on seasonal and temporal changes in soil enzyme activities (phosphatase and dehydrogenase). There were ten treatments each replicated four times viz., T1 - 50 % NPK, T2 - 100% NPK, T3 - 150% NPK, T4 - 100% NPK + hand weeding, T5 - 100% NPK + ZnSO4 , T6 - 100% NP, T7 - 100% N alone, T8 - 100% NPK + FYM, T9 - 100% NPK (-S) and T10 - Control. The results showed that during monsoon fallow period, dehydrogenase activity increased, while phosphatase activity recorded lower values after monsoon rainfall. Unlike phosphatase activity, dehydrogenase activity followed a declining trend as growth stages of hybrid maize (Co-6) proceeds. Among the treatments, 100 % NPK + FYM @ 10 t ha-1 (T8 ) recorded the highest activities of these enzymes emphasising the importance of integrated nutrient management in improving biochemical properties of soil, thereby sustaining the soil health over long run.