Effect of crop residues on growth and absorption of mineral elements of soil by sugarcane

Permanent cultivation of sugarcane and harvesting without any balanced and enough fertilization and get out or burn trashes in fields causes problems in soil fertility، minerals get out from soil that influenced on yield and usage fertilizers. The green house experiment carried out for evaluation effects of crop residue on three sugarcane varieties in split plot experiment based on CRB with three replication at Karoun Agronomy and Industry Company in 2008. there were six levels of crop residue treatment including of wheat، maize، sugarcane، medicago، cowpea and mungbean as main plot and three levels of sugarcane varieties treatment including of CP57-614، CP69-1062، CP48-103 as sub plot. The results showed that there were the greatest of foliar dry matter، root dry matter، total dry matter، leaf area index and P percentage by medicago residue and the greatest N percentage and K percentage by mungbean residue. There were the lowest of variables by sugarcane residue. There were the greatest of foliar dry matter، total dry matter، leaf area index، P percentage and K percentage by CP48-103 variety and the greatest of root dry matter and N percentage by CP57-614 variety.