مديريت تنش آبي جهت كاربرد بهينه آب و كود نيتروژنه در اراضي تحت كشت نيشكر

Using water stress management to optimization of water and nitrogen application on Sugarcane fields

جهت تعيين سطح بهينه آب مصرفي و عملكرد نيشكر، پژوهشي در قالب طرح كرت‌هاي خرد شده در سال 1386 در اهواز صورت گرفت. تيمارهاي آبي: آبياري كامل (I1)، 85% (I2) و 70% (I3) آبياري كامل بودند. نيتروژن نيز در سه سطح 150(N1)، 250(N2) و 350(N3) كيلوگرم در هكتار لحاظ شد. تاثير تنش آبي بر عملكرد ني و شكر در تيمار I1 نسبت به I3 معني دار بود و كاربرد تيمار I3 سبب كاهش عملكرد ني و شكر به‌ميزان 18 و 17 درصد نسبت به تيمارI1 شد. بين تيمارهايI1 و I2 اختلاف معني‌داري مشاهده نشد. تنش آبي بر كاهش عملكرد تاثير معني داري داشت اما علي رغم كاهش سطح آب و افزايش درجه خلوص شكر، كارايي مصرف آب در تيمارهاي آبي معني دار نشد. عملكرد ني و شكر در تيمار N3 نسبت به N1 به‌ميزان 26 و 20 درصد افزايش داشت. افزايش سطوح نيتروژن، افزايش معني دار كارايي مصرف آب را نشان داد كه بيانگر اهميت ويژه كاربرد ازت در كنار آب جهت ارتقا ميزان عملكرد است. بيشترين و كمترين عملكرد ني و شكر در تيمارهاي I1N3 و I3N1 مشاهده شد. تيمارهاي I3N3 و I1N1 بيشترين و كمترين مقدار كارايي مصرف آب را داشتند. بر اساس نتايج بدست آمده، تيمار آبي I2 براي كاربرد در كشت و صنعت اميركبير توصيه مي‌شود.

This study was conducted to determine the effect of water stress and nitrogen fertilization on sugarcane yield and the optimum irrigation and nitrogen levels. This experiment was conducted as a split plot with a randomized complete block arrangement at the experimental farm of Khuzestan sugarcane research center during in 2007. Irrigation treatments were full irrigation (I1), %85 (I2) and %70 (I3) of I1. N application consist of 150 (N1), 250 (N2) and 350 (N3) kg/ha. The results indicated that effect of stress on cane yield and sugar yield in I3 and I1 are significant and reductions of Cane and sugar yields were 18 and 17 percent respectively. But we did not observe significantly different between parameters in I1 and I2. Water productivity increased when the water use decreased, but this effect in spite of decrease of water using and increase of sugar purity was not significant because water stress had significant effect on sugar yield. Sugarcane responses to N application were more than irrigation treatments. Cane yield and sugar yield reductions were 26% and 20% in N1 comparison with N3. Water productivity was significant with increase of N application and these results showed that water use and N application are the important parameters to manage of sugarcane yield. Water production was decreased under irrigation treatments. The maximum and minimum cane and sugar yield was observed in I1N3 and I3N1, respectively. Highest and lowest Water productivity was observed in I3N3 and I1N1. According to results the I2 treatment was the best level to irrigation of Khuzestan sugarcane fields.