Impacts of soil fertility management on productivity and economics of rice and fodder intercropping systems under rainfed conditions in Odisha, India

Under small and marginal farm conditions, allocation of land exclusively for forages is not possible. Hence, integration of forages in existing crop geometry can ensure production of grain and fodder, simultaneously under rainfed conditions. A field experiment was conducted to study the effect of different nutrient management practices on rice and fodder intercropping systems under rainfed conditions during 2015–2017. The intercropping system comprised (i) sole rice (R), (ii) rice and cowpea (5:2) (CP) and (iii) rice and ricebean (5:2) (RB) whereas the different nutrient management practices comprised (i) application of farm yard manure (FYM) at 5 t ha–1 (farmers’ practice) (N1), (ii) application of inorganic fertilizer (recommended dose of fertilizer (RDF) of rice, 60:30:30 kg ha–1 of N:P2O5:K2O) (N2) and (iii) application of both FYM at 5 t ha–1 and 50% of RDF inorganic fertilizer (N3). The results of the experiment revealed that the growth attribute such as leaf area was influenced significantly when fodder crops were taken as intercrops because rice plant was getting more nitrogen from soil due to nitrogen fixation of leguminous fodder crops. Among the nutrient management practices, significant differences in leaf area were found beween N2 and N1, and between N3 and N1 treatments. However, regarding total number of effective tillers, significant differences were found neither between nutrient management practices nor between cropping systems. The rice equivalent yield (REY) based on price (REYP) was found to be significantly lower in CP (2 615 kg ha–1; –6.4%) and RB intercropping systems (2 571 kg ha–1; –8.0%) than in R monocropping system (2 794 kg ha–1). However, the REY based on energy (REYE) of CP (2 999 kg ha–1; +7.3%) and RB (2 960 kg ha–1; +5.9%) were found to be significantly higher than that of R (2 794 kg ha–1) irrespective of nutrient management practices. Between different nutrient management practices, the N3 treatment recorded the highest REYP and REYE which was at par with the N2 treatment and significantly higher than the N1 treatment irrespective of cropping systems. The combined application of both organic and inorganic sources of nutrients helped to supply nutrients throughout the growing season, which led to improved growth parameters and rice yield. The R monocropping system resulted in more income and rain water use efficiency (RWUE) closely followed by rice and fodder intercropping systems. However, the REYE and energy use efficiency (EUE) of rice and fodder intercropping systems were higher than those of R. Also, fodder helped to meet the requirement of cattle feeding in the off-season. Hence, the intercropping system is advocated in the study zone. Further study can be done on ecosystem services and carbon sequestration potential of the intercropping system, as well as the system’s coping ability in response to short drought through observing periodic soil moisture regime in root zone.