Effect of Nitrogen Levels and Foliar Application of Potassium Sulfate and Micronutrients on Growth and Yield of Maize Preceded By Wheat or Clover

Intensive crop rotation and imbalance fertilizer use have resulted in a wide range of nutrients deficiency in fields. For intensive cropping systems, the current recommended fertilizers rates need revision upwards with in balance ratio of vital micronutrients specific to crop to enhance stagnant yields. Two field experiments were carried out at the Agric. Exp. Sta., Fac. Agric., Cairo University, Egypt during 2014/2015 and 2016/2017 seasons to study the effect of preceding winter crops (Wheat or Egyptian clover), nitrogen levels (90, 120 and 150 kg N/fed.) and foliar minerals application (Control, potassiumsulphateand micronutrient compound of high zinc as well as their interaction) on growth and yield of Zea mays L. cv. single cross 131. The experimental design was split- split plot design with three replications. Results showed that maize planted after Egyptian clover provided the highest grain yield per plant (201.1 and 250.4 g), grain yield per fed. (3.474and3.487 ton) as well as harvest index (0.35 and 0.25 %) as compared to maize sown after wheat for both seasons, respectively. Increasing N rates from 90 to 120 kg/fed.and from 120 to 150 kg/fed.increased grain yield/plant by about 5.2% and 1.9% in the 1^st season, corresponding to 2.9 % and 1.9% in the 2^nd season, respectively. Increasing N rates from 90 to 120 kg/fed.and from 120 to 150 kg/fed increased grain yield/fed by about 24.6% and 12.8 % in the 1^st season, corresponding to 25.9 % and 12.1 % in the 2^nd season, respectively. Maize plants grown after Egyptian clover and receiving 150 kg N/fed.with the applied micronutrients and k foliarspray gave the highest grain yield/fed. (4.083 and 4.139 ton)in both seasons. The lowest value of grain yield/fed.was shown when maize was grown after wheat and receiving 90 kg N/fed.with foliar application of micronutrients and k sulfate in both seasons.Maize grown after Egyptian clover and receiving 120 kg N/fed.andfoliar application of micronutrients and k sulfate is recommended for maize production. On the other hand, maize grown after wheat withapplication of150 kg N/fed and foliar applicationof micronutrients and k sulfate is recommended for maize production.Regression analysis reveal the relation between the two variables, i. e., preceding crops (x) and Grain yield/fed (y) there was a linear relation, and, highly significant (P≤0.01) correlation coefficient (r=1) during the first and second seasons.  Linear regression equation for N rates suggested that increase in one unit (30 kg/fed.) led to increase grain yield/fed.by 0.35 ton/fed.during the first and second seasons.