水稻精量穴直播机开沟装置的设计与试验

为解决人工撒播与机械条播表土播种方式存在的苗难齐、产量不稳等问题,根据"精量穴播"、"开沟起垄"的技术思路,对水稻精量穴直播机同步开沟起垄装置的关键部件播种沟开沟器和蓄水沟开沟器进行了研究。根据同步开沟起垄的农艺要求确定适宜直播机水田作业的土壤(壤土和黏土)含水率为50%~58%,并确定了播种沟开沟器及蓄水沟开沟器的外形尺寸分别为50 mm×35 mm×30 mm、80 mm×50 mm×50 mm(上宽×下宽×高度)。对不同开沟方式对水稻出苗、水稻产量及其构成因素的影响进行了对比试验,试验设3个处理:开水沟+开播种沟+机械穴播(W1)、开播种沟+机械穴播(W2)、不开沟+机械穴播(W3),选用杂交稻品种培杂泰丰和常规稻品种玉香油占为试验材料。研究结果表明,与"不开沟+穴播"播种方式相比,开播种沟的播种方式不仅可以保证穴播方式的成行成穴齐苗生长,还可提高水稻出苗率(培杂泰丰提高了13.4%~17.8%,玉香油占提高了12.3%~16.0%);结实率与产量极显著相关,有效穗数与产量亦具有显著相关性。综合考虑3者的变化程度及趋势,"播种沟+水沟+穴播"播种方式总体优势明显,较不开沟播种方式,在水稻产量方面最高可提高8.10%,且始终保持相对最高产量的效果。开沟装置的设计以及大田试验的验证对水稻机械化穴直播技术的推广应用有重要的指导意义。

Design and experiment of furrowing device of precision hill-drop drilling machine for rice

Abstract: In general, manual rice broadcast seeding method has the problems of seedling without the same height, unstable yield, and so on. To solve these problems, the furrowing device of rice precision hill-drop drilling machine was designed and improved, on the basis of the technical idea of "precision hill-drop drilling" and "furrowing and ridging". The precision rice hill-drop drilling technology with synchronous furrowing and ridging was researched to meet the requirements of rice planting in order. It can create a ridge, open the seeding furrow on the ridge and the water furrow between the ridges synchronously, and sow pre-germinated rice seeds in the seeding furrow. The results of the test in Hunan, Shanghai and Guangdong showed that the suitable water content of loam and clay was between 50% and 58%. According to agronomic requirement of furrowing and ridging, the size of seeding furrow opener (50 mm × 35 mm × 30 mm) and the size of water furrow opener (80 mm × 50 mm × 50 mm) were determined. The furrower must meet the following demands: 1) Good forming effect of ridge and furrow; 2) The furrows had the same depth, and were formed neatly and straightly and could adapt to different mud surface; 3) Furrower would not be wrapped with grass; 4) Furrower was not attached with a large quantity of mud; and 5) Simple structure, light weight and light operation resistance. Based on the rice transplanting depth of about 20-40 mm and the width of seed bed, the seeding furrower had a size of 50 mm × 35 mm × 30 mm; according to the experiments, the water furrower had a size of 80 mm × 50 mm × 50 mm. The effects of different furrow opening methods on seedling-emergence, yield and its component were studied using the compared tests, and the methods included water furrow + seeding furrow + hill-drop drilling (W1), seeding furrow + hill-drop drilling (W2) and hill-drop drilling (W3). Hybrid rice variety (Peizataifeng) and conventional variety (Yuxiangyouzhan) were used as the materials and treated under W1, W2, and W3. The test was conducted in 2012 and 2013. The results showed that compared with the method without furrow, furrowing and ridging synchronously could not only ensure the seedling to grow orderly and evenly, but also increase the seedling emergence rate (17.8% for Peizataifeng, 16.0% for Yuxiangyouzhan). Furthermore, the grain-filling percentage (P<0.01) and effective panicle number (P<0.05) were significantly correlated to the yield. Analyses of the change degree and tendency of the 3 furrow opening methods were performed, and the result showed that obvious advantages were exhibited under the W1 treatment, which not only increased the yield by up to 8.10% (compared with W3), but also kept the highest yield while not affected by rice varieties and different years (compared with W2 and W3). Totally, the design of furrow opening device, the suitable mechanical factors and the results of field experiments can be of significance to the extending application.