Update of Mineral Fertilization Recommendations for Maize (Zea mays L.) in the Savannah Region of Togo

Abstract

The recommendations specific site of the nutrients in maize cultivation are necessary in the region of Savannah in Togo in the current context of the variability of the endogenous fertility of soils. To this end, based on the results of subtractive trials whose treatments were: the absolute control - N0P0K0 (T1), N0P60K70 (T2), N120P0K70 (T3), N120P60K0 (T4) and N120P60K70 (T5) kg ha-1 coupled with the maize variety Ikenne, conducted in the prefectures of the Savannah region, target yields were determined taking into account the potential yield of the Ikenne variety. Fertilization formulas to obtain the difference between the target yields and those measured on the zero N, zero P and zero K treatments were calculated. The results revealed that the gradient of priority nutrient requirement for maize was N > P > K in the prefectures. In Tandjouaré, grain yields of 3, 3.5, 4, and 4.5 Mg ha-1 were obtained with the fertilizer formulas N92P0K0, N112P10K0, N132P18K16 and N152P26K29 kg ha-1, respectively, with corresponding value/cost ratios of 16, 13, 11, and 10. In Tône, achieving grain yields of 2.5, 3, 3.5, 4, and 4.5 Mg ha-1 is subject to the fertilizer formulas N79P24K0, N99P32K16, N119P41K30, N139P49K43 and N159P57K56 kg ha-1, respectively, with corresponding value/cost ratios of 9, 8, 12, 7, and 6. In Oti, achieving grain yields of 3, 3.5, 4, and 4.5 Mg ha-1 is subject to the fertilizer formulas N66P7K0, N86P16K9, N106P24K22 and N126P32K36 kg ha-1, respectively, with corresponding value/cost ratios of 19, 14, 11, and 10. In Kpendjal, obtaining grain yields of 2.5, 3, 3.5, 4 and 4.5 Mg ha-1 is subject to fertilizer formulas N70P16K5, N90P24K18, N110P33K31, N130P41K45 et N150P49K58 kg ha-1, respectively, with corresponding value/cost ratios of 11, 9, 8, 7 and 7.