Site specific nutrient management for yield maximization in rice (Oryza sativa) wheat (Triticum aestivum) cropping system in north-western Himalayas

Abstract

A field experiment was conducted in a permanent layout for 7 consecutive years (rainy season 2007 to winter season (2010) at Palampur for yield maximization of rice (Oryza sativa L.)wheat (Triticum aestivum L.) cropping system through site-specific nutrient management. Twelve combinations of primary, secondary and micronutrients [T , N P K S B Zn , (figure as subscript indicate dose in kg/ha of N, P O , K O, S, Borax and ZnSO , respec- 1 100 25 120 40 5 20 2 5 2 4 tively) T , N P K S B Zn ; T , N P K S B Zn ; T , N P K S B Zn ; T , N P K S B Zn ; T ,N P 2 100 50 120 40 5 20 3 100 0 120 40 5 20 4 100 25 80 40 5 20 5 100 25 40 40 5 20 6 100 25 K S B Zn ; T , N P K S B Zn ; T , N P K S B Zn ; T , N P K S B Zn ; T , N P K S B Zn ; T , 0 40 5 20 7 100 25 120 40 5 0 8 100 25 120 40 0 20 9 100 25 120 0 5 20 10 100 25 120 0 0 0 11 RDF, (recommended dose of fertilizers, N P K for rice and N P K for wheat) and T , INM (integrated nutri- 90 40 40 120 60 30 12 ent management, N P K + 5 t FYM/ha for rice and N P K + 5 t FYM/ha for wheat]-based upon the available 36 16 16 48 24 12 nutrient status of the site were evaluated. N, P and K were applied to both the crops. S, B and Zn were applied to rice only. State recommended application of nutrients (T ) maintained its superiority for rice grain yield initially, 11 however, N P K S B Zn (T ) excelled over it at last. INM practice (T ) was lowest yielder in the early years 100 25 120 0 0 0 10 12 but at last next only after N P K S B Zn and RDF. The complete deletion of K application from N P K S 100 25 120 0 0 0 100 25 120 40 B Zn under T , resulted in significantly the lowest rice yield. In increasing wheat yield, N P K S B Zn main- 5 20 6 100 50 120 40 5 20 tained its superiority throughout and therefore, had the highest sustainable yield index. This was followed by N P K S B Zn , RDF and N P K S B Zn both in terms of yield and sustainability. The system productivity 100 25 120 0 0 0 100 25 120 40 5 0 (rice + wheat grain) ranged between 5.0 (N P K S B Zn ) to 12.7 t/ha (N P K S B Zn ) under different 100 25 120 0 0 0 100 50 120 40 5 20 treatments. The system productivity and sustainability index was higher under N P K S B Zn , RDF and 100 50 120 40 5 20 N P K S B Zn over other treatments. Among the soil properties, pH decreased significantly over the initial test 100 25 120 0 0 0 value of 5.3 in all the treatments except INM (T ). A definite build up of organic carbon over its initial value of 0.7% 12 was observed in N P K S B Zn , N P K S B Zn , N P K S B Zn , RDF and INM treatment. There was 100 25 80 40 5 20 100 25 40 40 5 20 100 25 120 0 0 0 depletion of available P in all the treatments over its initial test value of 50 kg/ha. There was significant build up of available K in N P K S B Zn , N P K S B Zn , N P K S B Zn , N P K S B Zn and INM treat- 100 25 120 40 5 20 100 0 120 40 5 20 100 25 120 40 5 0 100 25 120 40 0 20 ment over the initial status of 86 kg/ha. Available K was significantly low where no K or low K was applied. N P K S B Zn gave the highest benefit: cost ratio of 3.07 and was comparable to RDF in influencing total net 100 25 120 0 0 0 returns. N P K S B Zn resulted in the highest total apparent nutrient recovery, apparent N recovery and N 100 50 120 40 5 20 physiological productivity. P physiological productivity was the highest under RDF and K physiological productivity was the highest under N P K S B Zn . 100 25 0 40 5 20