Effect of Green Manure and Nitrogen Fertilizer on Cotton Fresh and Dry Matter Yield Distribution Among Different Plant Parts in AL-Ghab Plain.

Field experiment was conducted for two growing seasons (2009/2010 ,2010/2011) at AL-Ghab Center for Scientific Agricultural Research (Syria), (GCSAR) using split plot design with three replicates and sixteen treatments, to study the effect of two nitrogen sources fertilization the first : Mineral (Urea 46%) and the second: Organic (green manure with legume crops) and the impact of these two types of fertilizers on fresh and dry matter yield and distribution among different plant tissues of cotton crop (strain 124) under Al-Ghab plain conditions. Four levels of mineral nitrogen fertilization (0- 80-160-240 kg N.ha-1) and four treatments of green manure (GM0: without green manure, GM1: green manure with Faba Bean crop, GM2: green manure with peas, GM3: Green manure with Vetch) were used. The results showed that fresh and dry matter of cotton plant tissues(leaves, stems, fruiting forms) responded significantly to all levels of nitrogen fertilization,compared with control (without fertilization) on flowering and maturity stages. Green manure caused significant increase in fresh and dry matter yield, also inorganic nitrogen and green manure fertilizers caused significant increase in cotton lint yield, but this increase varies with the type of legume crops, which used as a green manure and with rate of inorganic nitrogen fertilizer application, the highest productivity cotton lint occurred at the treatment GM1N160, 1.82, 2.38 t.ha-1, an increase of (83.6, 73.15)% in both seasonal respectively, compared with control GM0N0 (without fertilization N and GM ) 0.99, 1.37 t.ha-1in both seasonal respectively, while the lowest productivity of cotton lint was found at the treatment GM2N0 (1.18, 1.61) t.ha-1 in both seasonal respectively. The cotton lint yield was correlated with fresh and dry matter yield which reached (0.63 ,0 .66) respectively in the first seasonal, and (0.75 , 0.76) respectively in the second seasonal.