Growth dynamics and nutrient content of winter maize(Zea maysL.)-based intercropping systems in relation to integrated nitrogen management under Indo-Gangetic plains of Uttar Pradesh

Abstract

Afield experiment was carried out for two consecutive winter (rabi) seasons of2013-14 and 2014–15 at Kanpur, India to find out the effect of integrated nitrogen management (INM) on growth dynamics and nutrient content of winter maize (Zea mays L.) intercropped with potato (Solanum tuberosum L.), Indian mustard [Brassicajuncea (L.) Czernj. & Cosson] and linseed (Linum usitatissimum L.) for Indo-Gangetic plains of Uttar Pradesh. The experiment consisted of three intercropping systems (maize + potato, maize + mustard and maize + linseed grown in 3: 1 row ratio) and three INM practices, viz. 100% recommended dose of nitrogen (100% RDN), 75% RDN through inorganics + 25% RDN through organics (75 + 25% RDN), and 50% RDN through inorganics + 50% RDN through organics (50 + 50% RDN) along with sole cropping of maize, potato, mustard and linseed. Results revealed that dry matter accumulation increased progressively due to each crop growth stage. Maize + potato (3: 1) intercropping system resulted in the highest dry matter accumulation plant−1 throughout the crop growth, followed by maize + linseed (3: 1). Amongst different INM practices, treatment with 75 + 25% RDN revealed the maximum dry matter accumulation plant−1 and plant height. Maize + potato intercropping system exhibited higher absolute growth rate (AGR) and crop growth rate (CGR) during all the stages of crop growth, followed by maize + linseed system. Maize + potato also recorded higher relative growth rate (RGR) throughout the crop growth, except between 90 to 120 days after sowing (DAS). Maize+mustard intercropping system recorded lesser values of AGR, CGR and RGR throughout the crop period. INM practices improved the AGR and CGR but RGR was improved during later growth stages (120 days onwards) only. Application of 75 + 25% RDN recorded higher values of AGR and CGR. This treatment (75 + 25% RDN) also improved the RGR up to 90 DAS but between 90 to 120 DAS application of 75 + 25% RDN lowered RGR as compared to 100% RDN; however RGR further improved during later growth stages (120 days onwards) due to application of 75 + 25% RDN. Application of 50 + 50% RDN recorded minimum values of these growth indices. Correlation studies indicated significant positive correlation of seed yield with DMA, AGR, CGR and RGR as well as combinations of most of the growth stages, except RGR 90–120 DAS, emphasizing the importance of higher growth rate during grand growth period for best yield accrual in winter maize.