Effects Of Different Tillage Forms On Soil Characteristics Of Sandy Chestnut Soil And Naked Oats Growth In The Northwest Plateau Of Hebei Province

In order to study the effects of different tillage forms on the growth and development of naked oats and soil characteristics in Bashang plateau in the northwest of Hebei Province, A long term positioned experiment was conducted with a naked oats cultivar pin 5 and on the sandy loam light chestnut soil land of No-tillage experimental field of Zhangbei Experimental Station Agricultural University of Hebei. from May to September in 2007. The main results are as follows:1. The bulk density of soil at 0-10 cm layer and 10-20 cm layer are always higher under the treatment of no-tillage than those of minimum tillage and the conventional cross tillage at pre-seeding, and the bulk density of soil at 0-10 cm layer of minimum tillage is higher significantly than the conventional cross tillage, the difference between minimum tillage and the conventional cross tillage at 10-20 cm is not evident. The bulk density of soil at 0-10 cm layer of no-tillage descended after reaping compared with pre-seeding, and the other two treatments is opposite. The bulk density of soil at 10-20 cm layer under three treatments all descended, and the difference of bulk density of soil among three treatments and two soil layers is indistinctive after reaping.2. The soil rigidity is almost the highest under the treatment of no-tillage, followed by minimum tillage and the conventional cross tillage at 5 cm, 10 cm, 15 cm, 20 cm and 0-20 cm layer at pre seeding. On the other hand, the soil rigidity is higher under the treatment of no-tillage than by the conventional cross tillage and minimum tillage at 5 cm and 20 cm layer after reaping, and the soil rigidity of other soil layers such as 10 cm, 15 cm and 0-20 cm layer are the highest under the treatment of no-tillage, followed by minimum tillage and the conventional cross tillage.In addition, the soil rigidity of no-tillage and minimum tillage is positively related to the depth of soil, but the soil rigidity at 0-15 cm descended gradually under the treatment of the conventional cross tillage, and ascended acutely at15-20 cm.3. The water content of soil under minimum tillage and cross tillage was significantly higher than no tillage at tillering stage merely.4. Soil respiration under the treatment of no-tillage is the lowest among different treatments and layers, and highest under minimum tillage at 0-10 cm and 0-20 cm layer, at the same time, soil respiration under conventional cross tillage is higher than others at 10-20 cm layer.5. Soil microbial biomass carbon is almost the highest under the treatment of minimum tillage among different treatments and layers. On the other hand, the changes under the treatments of conventional cross tillage and no-tillage are different. Soil microbial biomass carbon under the treatments of no-tillage at 0-10 cm layer and 0-20 cm layer are higher than the conventional cross tillage, and the soil microbial biomass carbon under the treatments of conventional cross tillage at 10-20 cm layer is higher than that of no-tillage.6. Soil active microbial biomass is almost the highest under the treatment of no-tillage, followed by minimum tillage and the conventional cross tillage. At 10-20 cm layer, the soil active microbial biomass of minimum tillage is higher than that of the conventional cross tillage, and the lowest is no-tillage. At 0-20 cm layer, the average soil active microbial biomass is the highest under the treatment of minimum tillage, followed by no-tillage and the conventional cross tillage.7. Soil respiratory quotient is almost the highest under the treatment of the conventional cross tillage, followed by minimum tillage and no-tillage, and soil respiratory quotient at 10-20 cm layer is higher under the treatment of the conventional cross tillage, followed by no-tillage and minimum tillage.8. Dry weight and distribution of root was measured within the experiment, the result showed that dry weight of root at 30-40 cm layer is almost the highest under the treatment of the conventional cross tillage, followed by minimum tillage and no-tillage. On the other hand, the distribution of root at 0-10 cm layer is almost higher under the treatment of the conventional cross tillage than the other two treatments except tillering stage, but dry weight of root under no-tillage is lower. The distribution of root at 10-30 cm layer under no-tillage treatment is the lowest. Root length, dry weight of root system, surface area of root system and volume of root system in soil are negatively related to the depth of the soil. Specific root length of no-tillage is positively related to the depth of the soil, at the same time, minimum tillage and conventional cross tillage is positively related to the depth of the soil except 40-50 cm layer.9. The plant height, Leaf Area Index and total stems of naked oats are almost the highest under the treatment of the conventional cross tillage, followed by minimum tillage and No-tillage, and the difference between minimum tillage and the conventional cross tillage is indistinctive, the difference among minimum tillage, the conventional cross tillage and no-tillage is apparent. The yield of naked oats is almost the highest under the treatment of minimum tillage, followed by the conventional cross tillage and No-tillage, and the yield under the treatment of no-tillage is lower significantly than minimum tillage and the conventional cross tillage. The water use efficiency is almost the highest under the treatment of minimum tillage, followed by the conventional cross tillage and No-tillage, and the difference among them is not significant.10. No-tillage has no work of tillage and saves manpower and material resources. The bulk density and rigidity of soil increases under the No-tillage, furthermore, it can affect the quality of seeding, seedling and the growth and development of crops, so the yield of naked oats decreases significantly. Minimum tillage reduces the tillage work than the conventional cross tillage, ecological efficiency and yield is much better. So the experiment reached a conclusion that minimum tillage is favorably feasible on the sandy loam light chestnut soil land in Bashang plateau in the northwest of Hebei Province.