Selection of Suitable Planting Method and Nutrient Management Techniques for Reducing Methane Flux from Rice Fields

Abstract

A field investigation was carried out during kharif season of 2004 at Crop Research Center, Pantnagar to know the effect of rice sowing and planting methods as well as nutrient management techniques on methane flux from rice fields. Performance of three planting methods viz., direct sowing, manual transplanting and transplanting by mat type rice transplanter and six nutrient management techniques viz., control, application of 100% NPK + Sulphur, 100% NPK + Azotobacter, 100% NPK + Farm Yard Manure (FYM), 100% NPK + wheat straw and vermicompost alone were assessed along with the control. The experiment was conducted in Split Plot Design (SPD) with 18 treatment combinations assigning planting methods as a main factor and nutrient management techniques as the sub factor. The experiment was replicated 3 times. On an average, direct sowing of rice recorded lowest methane flux (2.78 mg m−2 h−1) followed by transplanting with mat type rice transplanter (2.86 mg m−2 h−1) but manual transplanting recorded the highest methane flux i.e., 3.09 mg m−2 h−1. Among all the nutrient management techniques, application of vermicompost alone was found to be the most efficient measure for reducing methane flux (0.79 mg m−2 h−1) followed by control (1.26 mg m−2 h−1), Sulphur amendment (2.02 mg m−2 h−1), and Azotobacter (2.08 mg m−2 h−1). On the other hand, considerable higher methane flux was recoded in straw amendment (6.53 mg m−2 h−1) and FYM amendment (3.64 mg m−2 h−1). It was interesting to know that the combination of Vermicompost + direct sowing recorded the lowest methane flux (0.70 mg m−2 h−1) followed by Vermicompost + mat type rice transplanter (0.75 mg m−2 h−1) but it also reduced the grain yield of rice and can not be suggested. Further, the suitable treatment to achieve higher grain yield as well as reduced CH4 flux was combination of 100% NPK + Sulphur + Direct Sowing followed by 100% NPK + Sulphur + mat type rice transplanter that gave 66.24 and 66.67 q ha−1 rice grain yields with significantly lower i.e., 1.57 and 2.24 mg m−2 h−1 methane flux. These can be suggested to the farmers for reduced methane flux with higher grain yield.