Calibration accuracy of requirement factor and sorption studies for fertilizer recommendation

The inconsistent and incoherent approaches by fertilizer recommendations to index crop response has prompted the search for alternative approaches. Some of problems stem from overlooking fundamental soil properties that govern solution, which is where plant roots absorb nutrients growth. A comparison was made between two contrasting equilibration techniques evaluate their precision in estimating response. Sorption isotherms phosphorus (P) potassium (K) were compared requirement factors. Phosphorus sorption determined following batch technique. Potassium developed with graded K levels. factors both P a 6-week incubation four different levels fertilization. Cowpea (Vigna unguiculata), mustard (Brassica juncea), maize (Zea mays) used as test crops. growth parameters measured included biomass (g), height (cm), leaf area index. At harvest, yield (g pot−1) uptake (mg also recorded. Linear correlation studies carried out association treatments tested Results showed no significant difference (p < 0.05) methods, despite higher K. 1.7 9.8 times than respective response, although relatively similar weakly correlated sorption-estimated nutrient levels, indicating an overestimation nutrients. Therefore, deemed be more precise technique