Mechanization of Tillage and Seeding on the Sand Cultivating

本研究的目的是为温室沙土栽培床上机械化耕作和播种提供基础数据。在填满沙土的栽培床上，制作了带有旋转式和固定式的试验耕作装置，并进行了试验。得到了以下结果：1)耕作所需功率为0.2 ~ 1.4 kW，随土壤含水量的增加而增大。2)耕作前后土壤气相与土壤含水量的差异在5% ~ 3.0% （d.b.s）之间。当土壤含水率大于3%时，气相的方差增大到10 ~ 40%。这主要受砂的流动性，即干燥条件下的低休止角的影响。可以认为，在床上耕作的水分含量应在4%至6%之间。3)固定刀耕作所需拉力大于旋耕法，且气相增加量小于5%。固定刀不适合在床上使用。掺有持水物质的干土得到水分后，膨胀到分布位置，上升到沙面。与持水物质混合后，固相减少，气相减少明显小于对照。它在土壤物理性质上表现出与耕作相同的现象。用试验装置测定了包衣种子和凝胶种子的物理性能和放电速率。得到了以下结果：1)包衣种子的抗压强度为628 ~ 1251 gf。2)在腮红与种子链轮间隙0 mm处，涂层种子的放电精度约为90%。

The object of this study is to obtain the fundamental data for mechanization of tillage and seeding on the bed of sand cultivating in green house. Trial tillage apparatus attached with rotary and fixed tines working on the rails was fabricated and tested on the cultivating bed filled up the sand. The following results were obtained.1) The required power of tillage was the range of 0.2-1.4 kW and increased with increase of the moisture content of soil.2) The variance of the vapor phase of before and after tillage of the soil was within 5% until 3.0% (d. b.) of the soil moisture content. But the variance of the vapor phase increases to 10-40 % when the soil moisture content has more than 3 %. These are influenced by the fluidity of sand, that is, the low repose angle under the dry condition. It is thinkable that the moisture content for tillage on the bed is property between 4 and 6 %.3) Pulling force of the fixed knife for tillage required more than rotary tillage and furthermore the increase of vapor phase is less than 5 %. It is not suitable using the fixed knife for tillage apparatus on the bed.When the dry soil mixed with the holding water substance gets the water, it swells into the position of the distribution and rises up sand surface. The solid phase decreases by mixed with the holding water substance into the soil but the decreasing of vapor phase is remarkable smaller than control. It shows the phenomenon as same as tillage in physical property of soil.The physical properties and discharge rate in the coating seed and seed in the gel were measured by some trial experimental apparatus. The following results were obtained.1) Crush strength of the coating seed was the range from 628 to 1251 gf.2) Discharge accuracy of the coating seed is about 90 % at the O mm clearance between the blush and seed sprocket.