Bio-Fertilization Effect on the Foliar Content of Nitrogen (N), Phosphorus (P) and Potassium (K) of Two QPM Maize Varieties in Two Luvisols of Yucatan, Mexico

The efficiency of two Quality Protein Maize (QPM): Sac Beh (Sac) and Chichen Itza (Chich) to extract nutrients from the soil and export to the plants was evaluated by applying Bio-fertilizers (Bio) in combination with Chemical fertilizers (Chem) in two rhodic Luvisols of Yucatan Mexico with low (Lot 1) and high (Lot 2) intensive agriculture use. This work was conducted in the Uxmal Experimental Station of Yucatan Mexico. Three treatments were evaluated: 1) the Control, No Chem no Bio, 2) Chem (60-80-00) of Nitrogen (N), Phosphorus (P₂O₅) and Potassium (K₂O), and 3) the combination of Bio plus Chem (60-80-00 mycorrhizal fungi azospirillum bacteria) distributed in a Randomized Block Design with three repetitions. At silk stage, the opposite leaves of the ears were sampled and analyzed for Nitrogen (N), Phosphorus (P) and Potassium (K) reported in percentage (%) and compared with Critical Levels. The yields (t·ha^-1) were matched with the nutrient contents. The Sac was more efficient to extract N from the soil and exported to leaves than Chich in Lot 1 but Chich was more efficient than Sac in Lot 2. The two varieties showed foliar N contents below the critical levels in both lots, even with the application of fertilizers. In Lot 2 with higher P in the soil, any plant showed deficiencies including the Control (00-00-00). Deficiencies of K were determined in Sac-Lot 1 (1.60%) and Chich-Lot 2 (1.56%) just in the control (00-00-00) but not in Chem and Chem-Bio. This suggests that the absorption of native K in the soil was encouraged by the application of Chem and Bio. The deficiencies of K in the Control can be attributed to an antagonistic effect of the high contents of Calcium (Ca) and Magesium (Mg) over K in the soil.