Root production, soil organic matter, soil moisture, and sorghum yield in an alley-cropping system with Acacia saligna (Labill.) Wendl. and Gliricidia sepium (Jacq.) Walp. in the Hararghe Highlands, eastern Ethiopia
نام عام مواد
[Thesis]
نام نخستين پديدآور
A. Abdelkadir
نام ساير پديدآوران
R. C. Schultz
وضعیت نشر و پخش و غیره
نام ناشر، پخش کننده و غيره
Iowa State University
تاریخ نشرو بخش و غیره
1997
مشخصات ظاهری
نام خاص و کميت اثر
101
یادداشتهای مربوط به پایان نامه ها
جزئيات پايان نامه و نوع درجه آن
Ph.D.
کسي که مدرک را اعطا کرده
Iowa State University
امتياز متن
1997
یادداشتهای مربوط به خلاصه یا چکیده
متن يادداشت
A field experiment was conducted to study root production, soil organic matter, and moisture and sorghum yield in an alley-cropping system with Acacia saligna and Gliricidia sepium in the Hararghe highlands of Ethiopia. Tree hedgerows were planted on either side of a 4-m wide crop alley. Intra-row spacing between trees was 25, 50, and 100 cm. In October, 1994 and March, 1995 soil samples were taken at depths of 0-10 cm and 10-30 cm at 50 and 200 cm distance from the hedgerows using direct coring and mesh bags. Roots were separated from the soil by wet-sieving and root weight and root length density were determined. Measurements of soil organic carbon and total nitrogen to a depth of 0-60 cm were made. Field tensiometers were installed at 10, 30 and 60 cm depths. Soil water content was periodically monitored at similar depths. Sorghum grain yield, above-ground dry matter and height were determined. Acacia fine-root (usd\leusd2 mm) mass was significantly usd\rm (p\le 0.05)usd higher than for Gliricidia in the top 30 cm of soil. The presence of fine roots decreased by 55% and 40% for Acacia and Gliricidia, respectively, as the distance increased from 50 to 200 cm from hedgerows. Increase in tree root mass was accompanied by proportionally decreased crop root mass. Results of the March samples showed that the dry period is when trees allocate a higher proportion of carbon to the root system to stay competitive under the dry conditions. Leaf and twig dry matter of Acacia was significantly usd\rm (p\le 0.05)usd higher than for Gliricidia. Soil organic matter was lower by 20% and 10% in control and Gliricidia plots compared to Acacia plots. Soil moisture content and water potential measurements indicated that soil moisture was lower in Acacia plots than in the control and Gliricidia plots. Sorghum biomass, grain yield and height were significantly usd\rm (p\le 0.05)usd higher with Gliricidia and control than with Acacia. The sorghum yield reduction with Acacia could be largely due to competition for soil moisture.
موضوع (اسم عام یاعبارت اسمی عام)
موضوع مستند نشده
Agronomy
موضوع مستند نشده
alley cropping
موضوع مستند نشده
Biological sciences
موضوع مستند نشده
Forestry
موضوع مستند نشده
intercropping
موضوع مستند نشده
Soil sciences
نام شخص به منزله سر شناسه - (مسئولیت معنوی درجه اول )