Effect of crop sequences, crop residues, sulfur application and nfertilizer on wheat crop grown on sandy calcareous soil

الملخص EN

Under minimum soil tillage conditions a field experiment for four seasons (2009 and 2010) was conducted to detect the effect of integration between crop sequences and crop residues application as a soil management strategies, sapplication and n- fertilizer levels on some crops grown on the sandy calcareous soil of arab el-awamer experimental station, assiut governorate.

egypt.

at the fifth growth season, during the winter of 2010/2011 the field experiment was completed and wheat field experiment with 3 replications in a split split plot design was designed to study the response of wheat crop to the previous and continued eight soil management treatments in main plots, rates of powder elemental s (zero and 300 kg s/fed every season) in the sub plots and mineral nitrogen fertilizer levels (60 and 120 kg n/fed) in the sub sub plots.

the eight soil management treatments in main plot were four different crop sequences with crop residues completely removed (-cr) or with crop residues incorporated in soil surface layer 0-25 cm (+cr).

the different four sequences (depend on it's inclusions from legume crops) were:- sequence 1 = wheat - maize - wheat - maize - wheat (0% legume crops) sequence 2 = wheat - maize - clover - maize - wheat (25% legume crops) sequence 3 = wheat - maize - clover - peanut - wheat (50% legume crops) sequence 4 = wheat - peanut - clover - peanut - wheat (75% legume crops) the obtained results showed that wheat growth, np uptake at spiking expulsion, yield and yield components were increased significantly due to different soil managements strategies (different crop sequences with or without crop residues) as compared with continuous cereal crop sequence with crop residues completely removed.

also, the treatment sequence 4 + cr caused increases in grain, straw and biological yield of wheat estimated by 78.8%, 55.1% and 63.0%, respectively.

while, treatment sequence 3 + cr caused increases in grain, straw and biological yield estimated by 69.1%, 49.7% and 56.2%, respectively as compared with continues cereal crop sequence 1 (control).

furthermore, the increase was recorded in wheat grain yield of treatment sequence 4 + cr was significant as compared with treatment sequence 3 + cr.

sulfur application, at the rate of 300 kg/fed seasonally, induced significant improvement on wheat growth, np uptakes at spiking expulsion, yield and yield components as compared with the zero s.

nitrogen fertilizer levels at the rate of 120 kg n/fed, induced significant improvement on wheat growth, np uptake at spiking expulsion, yield and yield components as compared with 60 kg n/fed.

furthermore, the increases in grain yield, straw yield and biological yield were 12.2% 13.6% and 13.1%, respectively due to the rate of 120 kg n/ fed.

in legume cereal cropping system especially highly legume crop sequence (75 % legume crops) resulted in higher yield and yield components of wheat crop as well as powdered s-application at 300 kg s/fed seasonally and n-fertilizer level at 120 kg n/fed.

but the question, is the crop sequence including 75% legume crops will be suitable for all other crops (clover, maize and peanut.