Evaluating the nutrient assimilation and nutrient ratios of pulse crops in various yield zones

Abstract

Plant nutrient analysis is a valuable supplement for soil quality assessment. This research aimed to analyze the nutrient concentration (N,P,K,S) during critical growth stages of pulse crop in the varying yield zones and to compute optimum nutrient ratios required to enhance the productivity in low soil quality zone, to maximize the yield in medium quality zone and to sustain yield in high quality zone. The study was conducted in Virudhunagar district of Tamil Nadu (90o20'72'' N 77o20'70''E) during 2016–2018 and the soil properties at preplanting stage (Blackgram var. MDU1) and yield data at maturity stage were recorded. The average yield of 880 kg ha-1 in the high soil quality category was significantly higher than the other two zones which might be due to higher soil available nitrogen and phosphorus that reflected in the highest N and P contents in the crop. The average content of crop K in all the soil quality zones were above the critical value which is attributed to higher soil available K status. The mean sulphur concentration (0.11percent) in the low yielding zone of pulses was less than the critical value (0.2 percent) indicating deficiency status of S. The N/P, N/K and N/S ratios computed in this study 7.0, 1.26 and 11.18 respectively are to be considered as desirable nutrient ratios for obtaining higher yields of pulses and as a basis for conducting further nutrient uptake studies in similar agro climatic regions of the country.