Effect of integrated nutrient management on yield, quality and soil properties in Pea-Okra System in an Acid Alfisol

Abstract

The present investigation was carried out to study the effect of integrated nutrient supply on yield, quality and soil properties in pea-okra system in a field experiment conducted from rabi 2008-09 to kharif 2011 at the Experimental Farm of Department of Soil Science, COA, CSK HPKV, Palampur in a randomized block design with thirteen treatments replicated three times. The soil of the experimental site was silty clay loam and classified taxonomically as Typic Hapludalf with acidic reaction, medium in organic carbon, low in available N, medium in P and K at the initiation of the experiment. The treatments were control, 75, 100 and 125 % NPK alone, along with The results revealed that addition of 125% NPK with 10 t vermicompost ha-1 recorded highest pod/fruit yield of pea and okra during all the years as compared to rest of the treatments. Amongst the rate of vermicompost application, 10 t ha-1 proved better over 5 t ha-1 at 75, 100 and 125% levels of NPK. Lime application with graded doses of fertilizers viz. 75, 100 and 125% NPK also increased the yield of both the crops over 75, 100 and 125% NPK alone as well as control. Uptake of N, P, K, Ca, Mg, Fe, Cu, Zn and Mn by both the crops during all the years followed almost similar trend as that of their respective yields. Crude fibre and chlorophyll content in okra fruit and crude protein, total soluble solids, ascorbic acid, carbohydrate, reducing, non-reducing and total sugars in pea seed increased in treatments where 75, 100 and 125% NPK with either lime or vermicompost at 5 t ha-1 or 10 t ha-1 was applied as compared to 75, 100 and 125% NPK alone. There was build up of organic carbon, available N, P, K and exchangeable Ca and Mg due to lime or vermicompost application at 5 and 10 t ha-1 along with 75, 100 and 125% NPK over 75, 100 and 125% NPK alone. A decrease in the DTPA extractable Fe, Mn, Zn and Cu, different forms of soil acidities and Al and Fe was recorded in 75, 100 and 125% NPK with lime over 75, 100 and 125% NPK alone. However, application of vermicompost at 5 and 10 t ha-1 at their respective levels of NPK increased the different DTPA extractable micronutrients, pH and decreased the different soil acidities as well as Al and Fe. Benefit cost ratio was highest in 125% NPK followed by 100% NPK in pea and 125% NPK + lime followed by 100% NPK+ lime in okra. The highest net returns in (Rs.51705 ha-1) were obtained in 125 % NPK + vermicompost at 5 t ha-1 in pea and (Rs. 33239 ha-1) in 125 per cent NPK+ lime treatment in okra crop.