Establishment of Soil Fertility Gradient and Nutrient Dynamics in Lateritic Soil under Successive Crops of Fodder Maize (Zea mays L.) in Kerala, India
Priya Maria Jacob
Department of Soil Science and Agricultural Chemistry, College of Agriculture, Vellayani, Thiruvananthapuram, Kerala – 695522, India.
S. Visveswaran *
Department of Soil Science and Agricultural Chemistry, College of Agriculture, Vellayani, Thiruvananthapuram, Kerala – 695522, India.
B. Rani
Department of Soil Science and Agricultural Chemistry, College of Agriculture, Vellayani, Thiruvananthapuram, Kerala – 695522, India.
B. Aparna
Department of Organic Agriculture, College of Agriculture, Vellayani, Thiruvananthapuram, Kerala – 695522, India.
S. Sarada
Department of Vegetable Science, College of Agriculture, Vellayani, Thiruvananthapuram, Kerala – 695522, India.
Pratheesh P. Gopinath
Department of Agricultural Statistics, College of Agriculture, Vellayani, Thiruvananthapuram, Kerala – 695522, India.
*Author to whom correspondence should be addressed.
Abstract
Aims: To establish distinct soil fertility levels in the lateritic soil of Kerala using three successive crops of fodder maize under graded nitrogen, phosphorus and potassium (NPK) fertilisation.
Study Design: Fertility-gradient experiment with three fertility strips and three replications.
Place and Duration of Study: Instructional Farm, College of Agriculture, Vellayani, Kerala Agricultural University, Thiruvananthapuram, Kerala; three fodder-maize crop seasons (first crop: October–December 2023; second crop: March–May 2024; third crop: August–October 2024).
Methodology: Fodder maize (Zea mays L., var. African Tall) was grown in S₀ (unfertilized control), S₁ (100:100:100 kg ha⁻¹ N:P₂O₅:K₂O) and S₂ (200:200:200 kg ha⁻¹ N:P₂O₅:K₂O). Post-harvest soil samples were analysed for pH, organic carbon (OC), cation-exchange capacity (CEC), available N, P, K, Ca, S, Fe and Mn. Plant N, P and K concentrations and fresh fodder yield were recorded, and treatment means were compared using analysis of variance.
Results: Soil pH did not differ significantly among the strips. Organic carbon and CEC differed significantly, with S₂ recording 0.79% OC and 7.95 cmol (p⁺) kg⁻¹ CEC after the third crop. Available N, P and K after the third crop were 189.82, 9.10 and 105.44 kg ha⁻¹ in S₀; 417.60, 18.06 and 247.95 kg ha⁻¹ in S₁; and 597.15, 25.62 and 288.77 kg ha⁻¹ in S₂, respectively. Fresh fodder yield ranged from 12.65 to 57.90 t ha⁻¹ across strips and crop cycles.
Conclusion: Graded NPK application combined with successive fodder-maize cropping established contrasting soil fertility conditions suitable for subsequent soil test crop response (STCR) experimentation.
Keywords: Fertility gradient, fodder maize, lateritic soil, nutrient dynamics, organic carbon, soil test crop response