Integrated use of organic and inorganic nitrogen sources and levels of N in wetland rice (Oryza sativa) in eastern Uttar Pradesh

Abstract

Most of the eastern Uttar Pradesh soils are were applied basal and mixed in the soil. deficient in nitrogen. The N-use efficiency is Urea supergranules were deep-placed in rice about 30-35% only in wetland rice (Oryza at 8-10 cm depth at the centre of 4 hills of sativa L.). The factors affecting its each alternative row and column. The crop efficiency are rates, sources and time of was harvested in the first week of November application. Optimization of split application and grain yield was recorded on 14% of N as urea supergranules and prilled urea moisture. During the winter season wheat e in relation to growth stages of rice is the variety RR 21 was sown on 4 January 1987 approach being suggested for improving the and 28 December 1987 with N, P and K @ a nitrogen-use efficiency of rice (Singh and 60,60 and 40 kgha. Singh, 1988). Significantly equal grain yield of rice was The present study was made to obtained under 58 kg Nha applied through investigate the effect of different forms of prilled urea and half dose of prilled urea + urea with sources and doses of N on the half as farmyard manure. Similarly, grain growth and yield of rice and wheat (Triticum yield obtained with 87 kg Nha equalled that aestivurn L. emend. Fiori & Paol.). obtained with 58 kg Nha as urea and 29 kg The experiment was conducted during the Nha as farmyard manure. It is clear that half rainy and winter seasons of 1988-87 and to two-thirds of N can be substituted by 1987--88 at Crop Research Station, farmyard manure, depending upon the rate Masodha. The soil was clay loam with pH of application. However, substitution of - 7.5, electrical conductivity 0.09 mrnhos/cm, fertilizer N (urea) with wheat straw organic matter 0.42%, available phosphorus depressed the grain yield of rice, probably 17.5 kg/ha and N 135 kg/ha. Thirteen because of immobilization of N due to low N treatments (Table 1) were laid out in ratio in wheat straw. It was concluded that randomized block design with 4 replications. half to two-thirds of chemical N can be The plot size was 4 m x 4 m and rice variety substituted by organic N (farmyard manure) Sarjoo 52 was tested in both the years. The without any yield loss depending upon the nursery was sown on 17 June 1986 and 15 rate of N applied to rice crop. All the June 1987 and transplanted on 1 August treatments increased the graiti yield 1986 and 4 August 1987 at 20 cm x 20 cm compared with the control. During the spacing. Nitrogen was applied as per winter seasons treatments showed non- treatments and 60 kg P,O, and 40 kg K,O/ha significant effect.