MANAGING NITROGEN REQUIREMENTS FOR MAIZE CROP GROWN ON SANDY SOIL USING FOLIAR APPLICATION OF NITROGEN AND ZINC WITH BIO-FERTILIZATION.

Abstract

The integration among nitrogen mineral fertilization, foliar application of micronutrients and inoculation with bio-fertilizers become necessary to save mineral nitrogen fertilizers and increase the productivity of maize yield and its quality. As for, a field experiment was carried out during the two successive summer growing seasons 2013 and 2014 in sandy soil at El-Sharawy village in EL-Bostan area – Noubaria Region, Elbeheira governorate (Latitude 30° 43' 22.01 N, Longitude 30° 16' 44.50 E), to study the response of maize (Zea maize L.) yield and its components to mineral nitrogen fertilization rates as soil and foliar application and zinc-EDTA foliar application with bio-fertilizer. Treatments were carried out as split split plot design with three replicates; the main plots were bio-fertilizer without (Bio0) and with (Bio1); the split plots were two levels of Zn-EDTA foliar application, Zn0 (without foliar) and Zn1 ( with foliar 0.06 % Zn-EDTA), and the sub split plots were five rates of nitrogen fertilizer (N1: 100 % of recommended N (RN) fertilizer as soil application; N2:75 % RN + 1% N foliar at two times, N3: 75 % RN + 1% N foliar at three times, N4: 50 % RN + 1% N foliar at two times and N5: 50 % RN + 1% N foliar at three times). The most important results could be summarized as follows: Application of N-fertilization rates, foliar Zn-EDTA and inoculation with bio-fertilizer have a significant effects on all studied parameters such as plant height, ear weight/plant, grain and stalks yields, 100-grain weight, percentage of carbohydrate, oil and protein, concentrations and uptake of N, P, K and Zn by maize grain. Where, grain yield increased by 12.81% with bio-fertilizer inoculation and by 7.13% with Foliar Zn-EDTA. The interaction between zinc and bio-fertilizer significantly increased plant height, ear weight/plant, 100-grain weight, concentrations and uptake of phosphorus and zinc, also the interactions between N-rates and bio-fertilizer have significant effects on 100-grain weight, grain yield, concentrations and uptake of phosphorus and zinc. Moreover, the interaction between N-rates and foliar Zn-EDTA has significant effect on maize grain yield. Also, the interaction among N-rates, Zn and bio-fertilizer have significant effect on ear weight/plant, stalks yield, 100-grain weight, oil %, concentrations and uptake of N, K and Zn by grain. Whereas, the superiority was for interaction N3*Zn1*Bio1 that achieve the highest relative increase % for ear weight, grain and stalks yields, carbohydrate %, oil % and protein % (13.03, 27.82, 18.53, 4.14, 16.10 and 11.16 %, respectively).