Integrated Nutrient Management of Rice Soil in Hilly Region of Meghalaya, India

An experiment was conducted to study the effect of integrated use of inorganic fertilizers (S and Zn coupled with recommended doses of NPK) in conjunction with organic manure (FYM) on availability of different macro and micro elements including organic carbon in a hilly soil of Meghalaya, India. Two Field trials were conducted consecutively for 2 years (2013-14 and 2014-15) with Rice variety Arize-6444 at Nongpoh village in Ri-Bhoi District of Meghalaya to fulfil the objectives of the experiment. The field experiment was conducted following Randomized Block Design. Altogether 11 treatments with 3 replications were included in the experiment. Results revealed that irrespective of treatments, exchangeable NH4+, soluble NO3‑, available P2O5 and K2O decreased with the period of crop growth. However, changes in organic C in soil showed an opposite trend of results. Regardless of treatments, organic C content enhanced with increment in the age of rice crop. Among the treatment combinations, significantly higher amount of exchangeable NH4+, soluble NO3-, available P2O5 and K2O is accumulated in the soil which received recommended doses of N, P and K along with FYM at 10 tonnes ha-1 as well as 40 kg S ha-1 and 5 kg Zn ha-1 (T8). Results further pointed out that balanced fertilization increased the availability of nutrients (particularly N, P and K) which maintained throughout the cropping season of rice. However, SO4-2-S content reduced with crop duration. No drastic variation is observed in DTPA-extractable Zn content in soil over the whole cropping season of rice. Incorporation of FYM in the treatment combinations improved and maintained available nutrients including organic C in soil particularly in the 2nd season of rice cultivation.