Influence of rice straw incorporation and integrated nutrient management on growth, yield, and nutrient uptake in potato (Solanum tuberosum) and onion (Allium cepa) under rice (Oryza sativa)–potato-onion cropping system

A field experiment was conducted during 2019–20 at the Punjab Agricultural University, Ludhiana, to study the influence of rice (Oryza sativa L.) straw incorporation and integrated nutrient management on growth, yield and nutrient uptake of potato and onion (Allium cepa L.) in direct-seeded rice (DSR)-potato (Solanum tuberosum L.)–onion cropping system. The experiment was laid out in a split-plot design, consisting of 4 rice residue and nutrientapplication treatments in potato in main plots and 4 nutrient application treatments in onion in subplots, replicated 4 times. Results showed that, growth and yield-attributing characters of potato increased significantly with the incorporation of rice residue and application of FYM. Tuber yield (34.0 t/ha) as well as nutrient uptake was significantly higher when rice residue was incorporated with 100% recommended dose of fertilizer (RDF) + 50 t/ha FYM in potato. Growth and yield attributes of onion were significantly higher with the application of 100% (RDF) + 50 t/ ha FYM along with the incorporation of rice residue in preceding potato and among the nutrient application treatments in onion, 100% RDF + 50 t/ha FYM treatment was significantly superior to rest of the treatments. Significantly higher bulb yield was also obtained under these treatments. The interaction between rice residue and nutrient-management treatments in potato and nutrient-application treatments in onion was significant for bulb yield of onion, which was significantly higher with the combination of 100% RDF + 50 t/ha FYM treatment in onion when rice residue was incorporated with 100% RDF + 50 t/ha FYM in preceding potato (35.8 t/ha) than all other treatment combinations, but it was statistically at par with the application of 100% RDF alone in onion when preceding potato received the same level of nutrients. Thus, in DSR-potato–onion cropping system, 50 t FYM/ha could be saved in onion crop when previous potato crop was supplied with 100% RDF + 50 t/ha FYM along with rice– residue incorporation without any yield reduction.