~ 1626 ~ International Journal of Chemical Studies 2019; 7(1): 1626-1629 P-ISSN: 2349–8528 E-ISSN: 2321–4902 IJCS 2019; 7(1): 1626-1629 © 2019 IJCS Received: 17-11-2018 Accepted: 20-12-2018 Alka Arya Department of Soil Science, College of Agriculture, G.B. Pant University of Agriculture & Technology Pantnagar, Uttarakhand, India Sobaran Singh Department of Soil Science, College of Agriculture, G.B. Pant University of Agriculture & Technology Pantnagar, Uttarakhand, India Pradeep Dey Indian Institute of Soil Science, Bhopal, Madhya Pradesh, India Correspondence Alka Arya Department of Soil Science, College of Agriculture, G.B. Pant University of Agriculture & Technology Pantnagar, Uttarakhand, India Prediction of post-harvest soil test values and apparent nutrient balance after cauliflower ( Brassica oleracea L var. botrytis) in Mollisol Alka Arya, Sobaran Singh and Pradeep Dey Abstract A Field experiment was conducted at Vegetable Research Centre, G.B. Pant University of Agriculture and Technology Pantnagar, Udham Singh Nagar (Uttarakhand) during 2015-16. The experimental site was located at 29° N latitude, 79° 27’ E longitudes and at an altitude of 217 m above the mean sea level. The experiment was conducted as per technical programme of All India Coordinated Research Project (AICRP) on Soil Test Crop Response (STCR) to develop Post harvest soil test values (PHSTVs), prediction equations adopting Inductive cum Targeted yield model [13] , after cauliflower (Brassica oleracea L var. botrytis). The experiment was laid out in a fractional factorial design comprising twenty four treatments (21 fertilizer treatments + three controls) using pre-sowing soil test values, fertilizer doses and Curd yield and/or NPK uptake by the crop as independent variables and post-harvest soil test values as dependent variable, for developing prediction equations. Significant R 2 values (>0.67) were recorded for prediction equations which showed that these equations could be used for the prediction of post-harvest KMnO4-N, Olsen-P and NH4OAc-K. Apparent nitrogen, phosphorus and potassium balances were found 9.67%, -32.76 and –4.22%, respectively in cauliflower. Using the predicted post- harvest soil test values of cauliflower, soil test based fertilizer recommendation for desired yield targets of any succeeding crop could be made. Keywords: Mollisol, postharvest soil test values, soil test crop response, cauliflower, prediction equation Introduction Soil testing is an important tool for crop production and soil fertility management. A sound soil testing program for rational and judicious fertilizer use to obtain desired crop response must be based on critical soil fertility limits of different nutrient elements in soils of the area. Soil testing is an important approach for predicting the fertility status of soil plant nutrient viz, nitrogen, phosphorus and potassium alone or in combination affect yield vis-a-vis nutrient uptake. Sound soil test crop response correlation studies help in making fertilizer recommendation for better yield of crop and in cropping sequence. Such studies are crop, soil and climate specific [12] . The soil test calibration and fertilizer recommendation must be based on yield which should provide significant correlation between soil test and crop response to fertilizer [14] . Soil testing has to be rechristened as soil quality assessment and it has to assume a holistic role not limited to guide fertilizer recommendation for a crop based on soil test but also for a sustainable crop production. Nutrient availability in the soil after the harvest of a crop is much influenced by the initial soil nutrient status, the amount of fertilizer nutrients added and the nature of the crop raised. To apply soil test based fertilizer recommendations, the soils are to be tested after each crop, which is not practicable. Therefore, it has become necessary to predict the soil test values after the harvest of the crop. It can be done by the development of prediction equations [12] . This provides the way for giving the fertilizer recommendations for whole cropping sequence based on initial soil test values. This is very useful because the soil of farmer’s field under intensive cultivation cannot be tested for each crop for practical reasons. In present study, an attempt has been made to predict the post- harvest soil test values for cauliflower and analyzed apparent nutrient balance for next crop. Materials and methods A field experiment was conducted as per the technical program of AICRP on Soil Test Crop Response Correlation (STCR) at Vegetable Research Centre (VRC), G.B. Pant University of Agriculture and Technology Pantnagar, Udham Singh Nagar (Uttarakhand).