Synergetic effect of N-P fertilization on growth, yield and nutrients content of corn and wheat plants grown on sandy soils amended with bentonite or compost

الملخص EN

The synergetic effect of N-P fertilization on growth, yield and nutrient content of corn-wheat sequence cropping pattern cultivated on loamy sandy soil amended with 5 ton/fed organic compost or bentonite shale was tested.

Three levels of N (100, 150 & 200 kg/fed for corn and 80, 120 & 160 kg/fed for wheat) in the form of NH4(SO4)2 (20.6% N) combined with three levels of P2O5 (40, 60 & 80 kg/fed for corn and 15.

30, 45 kg /fed for wheat) in the form of superphosphate (15% P2O5).

Obtained results showed that plant growth and yields of both straw and grain of corn increased with increasing the rate of N-P, particularly in the compost amended soil treated with 200 kg N/fed + 80 kg P2O5/fed.

This may be due to the applied organic compost accelerated the appearance of N-P synergism.

Synergetic action of P on N utilization, vice versa, continued to act in N and P incorporation by corn plants particularly those fertilized with heavy N and P rates.

Although K content had no clear response to N-P interaction, response of Ca and Mg contents behaved a relatively different trend, where they increased as one of the interacted nutrients of N or P, increased vs another one decreased.

The synergetic nature of N-P fertilization, each other, continued to act on wheat growth and yield with long term superiority for bentonite shale or organic compost was observed as compared to influence on corn cultivation.

In general, this is true although organic compost continued to result in higher growth and straw as well as higher quantity and quality of grain yield, as compared to bentonite and untreated soils.

Contents of N, P and K in wheat plants were, generally, positively responded to the N-P synergism although the applied soil amendments (organic compost and bentonite shale) disappeared the response of P content but accelerated the response of K as well as Ca content in the studied loamy sand soil.