List of Articles Contour line tillage

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  1 - Effect of Tillage Direction and Straw Mulch on Precipitation Use Efficiency in Wheat Rainfed Land in a Semi-Arid Region
  Alireza Vaezi Samira Rezaeipour Mohammad Babaakbari Fereshteh Azarifam
  Background and aim: Soil properties and management methods can affect plant growth and crop yield in agricultural areas. Rainfed agriculture is a dominant farming type in the world, which covers about 80% of the world's cultivated land and about 67 % of agricultural lan More

  Background and aim: Soil properties and management methods can affect plant growth and crop yield in agricultural areas. Rainfed agriculture is a dominant farming type in the world, which covers about 80% of the world's cultivated land and about 67 % of agricultural lands in Iran. Most of rainfed lands are in slope areas and tilled along slope, an incorrect method which accelerates water erosion. Controlling soil erosion and storing precipitation water in soil is the first step to conserve soil and water resources and increasing crop yield in rainfed lands. The change of tillage direction from along slope to contour line and maintaining crop residues can affect water loss, Precipitation use efficiency (PUE) and crop yield in rainfed areas. This study was carried out to investigate the effect of tillage direction and wheat straw mulch on water loss, crop yield and precipitation used efficiency in a winter wheat rainfed land. Methods: The study was carried out in a rainfed lands with sandy loam soil under a slope of 10% in west of Zanjan, North West of Iran. field experiments were conducted at two tillage direction: along slope and contour line, and five wheat straw mulch application levels (control, 25, 50, 75 and 100%) with three replications. Precipitation data (height, duration and intensity) was taken from the Agricultural Meteorological Station located in the University of Zanjan, about 800 m from the study field. Winter wheat was cultivated at the plots early autumn and harvested early summer. Water loss from the plots was measured for each rainfall event resulting runoff at the plots during nine months growth period. Wheat grain yield was determined for each plot and accordingly precipitation use efficiency (PUE) in kg/ha.mm was computed based on wheat grain yield (kg/ha) per effective precipitation during growth period (mm). Soil properties and winter straw mulch characteristics were determined using the conventional methods in the lab and the variance analysis was used for determination of independent effect of tillage direction and straw mulch level and interactions between the two factors. Results: Eighty-two precipitation events were occurred in the area during a 9 months winter wheat growth period, which rainfalls included 88% from it. Most of rainfalls occurred in October that resulted most water loss at the plots. Water loss at the plots tilled contour line was 14% lower than the plots tilled along slope. However, water loss between the two tillage directions was no significant, whereas wheat grain yield as well as PUE were significantly affected by tillage direction. Straw mulch considerably affected on water loss, wheat grain yield and PUE. An obvious decrease was found in water loss with increasing in straw mulch level. The lowest water loss among different mulch levels was in 100% mulch level for the two tillage directions (63% for along slope tillage and 64% for contour line tillage). Significant interaction of the two factors was observed just for wheat grain yield. The highest wheat grain yield was in 75% mulch level which was about 27% (2.04 ton/ha) and 34% (2.45 ton/ha) bigger than control treatment, respectively. The highest PUE was also in 75% mulch level both in along slope tillage (7.2 kg/ha.mm) and contour line tillage (8.6 kg/ha.mm), which was 27% and 34% higher than control treatment, respectively. Conclusion: Results show the precipitation use efficiency (PUE) is an improper index for evaluation of the role of precipitation in crop production in wheat rainfed lands. This index can be affected by both tillage direction and wheat straw mulch application in rainfed lands. These two management methods are independent factors which affects strongly on the wheat grain yield and in consequence on the PUE. The change of tillage direction from along slope to contour line along and application of 75% mulch level (equal to 4.5 ton/ha) are proper strategies for conservation of soil and water and improving the utilization of precipitation in wheat rainfed lands. Manuscript profile