Changes in agrophysical properties of eroded leached chernozem during its agricultural use
2009
Smirnova, L.G., Belgorod Research and Development Inst. of Agriculture (Russian Federation)
A long field permanent experiment was established in the Belgorod region on a slope of the North-East exposition with steepness of 1-5 degrees. Agricultural crops were cultivated in grain feed soil protection crop rotation (corn for silage – barley with holy clover additionally sowed – holy clover – winter wheat. Mineral fertilizers and manure were applied in soil in different expediential variants. Over the 16-year period of agricultural use of chermozem leached eroded in tillage soil (0-30 cm) there was an increase in the number of particles of physical clay, this process was not observed deeper. Soil consistency increased to 1.26-1.29 g/cub.cm exceeding the optimum value (1.20 g/cuber cm). The aggregate composition of chernozem greatly changed. The number of cloddy fractions decreased from 5.7-9.2% to 15-29%; the number of pulverescent fractions decreased from 5.2-10.0% to 1.4-7.0%. The content agronomically valuable fraction decreased from 82-86 to 67-82%. The number of water-stable aggregates reduced from 47-53 to 39-48%. In the variant of combined application of manure and mineral fertilizers this process occurred only for the first 8 years of the experiment. Hygroscopic moisture increased from 5.9-6.7 to 7.0-7.5 mm. maximum hygroscopic moisture – from 10.9-12.0 to 14.2-14.6 mm, the index of wilting moisture is from 14.2-15.6 to 18.8-19.6 mm. The most reserves of productive moisture in tillage soil were observed in spring period in 4 rotation, the least one – in 2 rotation. The main reason for changing agro-physical properties was the compaction with agricultural equipment; no influence of fertilizer on these characteristics was found
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