Critical limit of boron for maize (Zea mays L.) in red and lateritic soil of Jharkhand, India

To establish a critical limit in soils and plant, an experiment was conducted in red and lateritic soil (Alfisols) of farmer’s field in tribal-dominated Panchayat Kurum, Palkot block, Gumla district, Jharkhand, India. Based on the results of the field experiment, the critical limits were determined as 0.48, 0.50, 0.47, and 0.42 mg kg⁻¹ in the soil, respectively, for hot water, hot calcium chloride, salicylic acid, and ammonium acetate-extractable B, while a critical limit of 12.00 mg kg⁻¹ was observed in maize tissue using the graphical method. In an analysis of variance method, the critical limits of B in soils were found as 0.45, 0.54, 0.49, and 0.43 mg kg⁻¹ using hot water, hot calcium chloride, salicylic acid, and ammonium acetate extractants, respectively. Maize plants were highly responsive to B application where soil B level was below the critical limit (0.50 mg kg⁻¹). In a field experiment, grain yield of maize increased with increasing levels of B application, while soil application at 1.0 kg ha⁻¹ + two foliar application (at the knee and pre-flowering stages) of borax at 0.2% were showed significantly higher grain yield of the maize crop. The hot water, hot calcium chloride, salicylic acid, and ammonium acetate-extractable B were significantly and positively correlated with organic carbon and negatively correlated with the electrical conductivity of soils. AA: Ammonium Acetate; AAS: Atomic Absorption Spectrophotometer; ACZ: Agro Climatic Zone; B: Boron; Ca: Calcium; cmol(p+) kg–1: Centimole (+) per Kilogram; Cu: Copper; DAS: Days After Sowing; dS m–1: DeciSiemens per Meter; DTPA: Diethylene Triamine Pentaacetic Acid; EC: Electrical Conductivity; Fe: Iron; HW: Hot Water; mg kg–1: Milligram per Kilogram; Mg: Magnesium; Mn: Manganese; OC: Organic Carbon; q ha–1: Quintal per Hectare