Effect of crop management using rotation and integrated fertilization system on seed yield and soil biological characteristics in sunflower cultivation.

The experiment was carried out in the research farm of the Faculty of Agriculture of Tarbiat Modares University in 2010 and 2009 for two years. The plants was sown in the crop rotation included vetchlings (Lathyrus sativus L.) as green manure and sunflower as the main crop and canola as fodder in the fall season. The experimental design was in the form of a split plot design based on randomized complete blocks with three replications, in which the main factor was the rotation system on 2 levels with and without green manure, including 1- green manure-sunflower-green manure- sunflower (GM) and 2- fallow-sunflower-fallow-sunflower (Fa) and the sub-plots were 5 types of nutritional systems including 1- zooponics organic fertilizer (Z100), 2-integrated fertilizer (75% organic zooponics + 25% chemical fertilizer (urea based on soil test) (Z75F25), 3- integrated fertilizer (50% organic zooponics + 50% chemical fertilizer) (Z50F50), 4- integrated fertilizer (25% organic zooponics + 75% chemical fertilizer) (Z25F75) and 5- fertilizer Chemical urea (F100). The results showed that the highest seed yield was obtained in the 100% chemical and 100% zooponics, and then in the 50% chemical + 50% zooponics fertilizing systems. Integrated feeding systems in both rotations efficiently increased the amount of soil organic matter.The fallow treatments had a higher amount of soil microbial biomass carbon and microbial respiration than the green manure treatments. The combined analysis of the data of two years of the experiment for the ratio of C/N showed that rotation had a significant effect and the mean comparison of the treatments showed that this ratio was higher in the fallow. Among the different fertilizing systems, 100% zeoponics treatment showed the highest ratio of C/N, and the lowest amount was found in 25% zeoponics + 75% chemical fertilizer. In general, by implementing integrated plant nutrition management through the use of green manure, zooponics and chemical fertilizers as an ecological approach, it is possible to achieve sustainable agricultural systems with the aim of reducing the consumption of chemical fertilizers and increasing the productivity of the soil.