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Field experimental study on optimal design of the rotary strip-till tools applied in rice-wheat rotation cropping system

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International Journal of Agricultural and Biological Engineering 2018年第2期11卷 88-94页

作者： Yanshan Yang John Fielke Qishuo Ding Ruiyin He College of Engineering Nanjing Agricultural UniversityNanjing 210031China School of Engineering University of South AustraliaMawson LakesSA 5095Australia

The rice-wheat rotation system plays a significant role in Asian *** introduction of strip-tillage into the rice-wheat system for wheat planting offers a way to use conservation tillage practices to improve the seedbed quality,retain residue between rows and reduce energy input.A field experiment was conducted using an in-situ test *** types of blade(bent C,straight and hoe)were evaluated in four tool configurations at four rotary speeds(180 r/min,280 r/min,380 r/min and 510 r/min)in a paddy *** shape parameters,tillage-induced soil structures and energy consumption were *** showed that the straight blade configuration failed to create a continuous furrow at either 180 r/min or 510 r/*** bent C blade configuration produced a uniform furrow profile but its furrow backfill was poor and unsuitable for *** hoe blade configuration cut a continuous furrow and better tillage-induced soil structure,but it produced a much wider and non-uniform furrow *** mixed blade configuration(central hoe blades with two straight blades aside)provided a uniform furrow with good backfill and fine tilth by utilizing both the cutting effect of straight blades on the furrow boundaries and tensile fracturing of the furrow soil by the hoe *** torque of the mixed blade configuration was comparable with the bent C blade but was less than the hoe ***,a mixed blade configuration was recommended for rotary strip-tillage seeding using in rice-wheat system.

关键词： strip tillage rotary strip-till tool blade configuration furrow quality tilth torque rice-wheat rotation system

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Suction Cup Samplers for Estimating Nitrate-Nitrogen in Soil Water in Irrigated Sugarbeet Production

引用

Journal of Environmental Protection 2016年第10期7卷 1342-1354页

作者： Jay D. Jabro William B. Stevens William M. Iversen Brett L. Allen Upendra M. Sainju USDA-ARSNorthern Plains Agricultural Research Laboratory Sidney MT USA

Efforts have increased to measure nitrate losses from farmland under different management practices due to environmental and public concerns over levels of nitrate-nitrogen (NO3-N) in surface and ground waters. This study evaluated the effect of conventional tillage (CT) and strip tillage (ST) practices and three N application rates on NO3-N concentrations in soil water at a 76 cm depth under irrigated sugarbeet (Beta vulgaris L.) in a clay loam soil. Nitrogen rates were applied as dry urea at 120, 150, 180 kg N ha-1 in 2006;130, 160, 190 kg N ha-1 in 2007;and 110, 140, 170 kg N ha-1 in 2008. Soil water volumes were measured weekly during each growing season using three ceramic suction cup samplers per plot placed at a 76 cm depth below the soil surface under each tillage. Results indicated that NO3-N concentrations at the 76 cm depth in the soil profile were not significantly affected by either tillage practice or by N application rate due to soil variability across the field and due to suction cup samplers’ biased estimate of soil water. The three N rates under CT and ST practices maintained NO3-N concentrations below the root zone to levels exceeding the 10 mg L-1 safe drinking water maximum level in all three years. There were large variations in NO3-N concentrations among replicates within each tillage and N rate that were likely caused by variability in soil physical, hydraulic and chemical properties that impacted water movement through the soil profile, N dynamics and leaching below the root zone of sugarbeet. In conclusion, suction cup samplers are point water measurement devices that reveal considerable variability among replicates within each treatment due to the heterogeneity of field soils. Further, these samplers are not recommended in heterogeneous soils with preferential flow characteristics.

关键词： Suction Cup Samplers Nitrate-Nitrogen Sugarbeet strip tillage Conventional tillage

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