紅豆播種裝置之性能測試與改良

Abstract

紅豆是台灣南部秋冬之季的重要經濟作物之一，主要產於高屏地區，並且大部分供應給國內市場。自台灣加入世界貿易組織(WTO)之後，台灣紅豆價格不穩且比進口之紅豆高；但因為台灣紅豆的品質好，仍受消費者喜愛。因此降低成本、提高種植效率為待解決問題。為了降低單位面積所要的種子與人力成本，本文探討播種機構，所可播散的種子能符合紅豆不整地穴播行距30公分、株距21公分、每穴2株之規格要求。本研究對某農機工廠研製之機械式星輪團播機構進行性能測定與改良，重點放在測定原本厚度7 mm與改良後厚度3 mm之播種轉盤於4 km/h、5 km/h、6 km/h、7 km/h、8 km/h以及9 km/h的工作速度下，其播種量、準確度、缺種率和多重播種率之情況。實驗中以輸送皮帶承接種子，並以交流伺服馬達帶動輸送皮帶和播種裝置之驅動軸，之間的齒輪組使輸送皮帶每行走21 cm播種裝置落種一次，當紅豆分佈於整條輸送皮帶上時，以人工量測種子間距，並以軟體(MATLAB)做數據之計算與統整。 結果顯示，為使播種裝置能正常工作，加裝種子擋板、掃除器以及擾動器是必要的。在播種量方面，原本的轉盤播種量遠超過理想之播種量，而改良之播種盤在低工作速度有達到理想之播種量；而高速時播種量則下降至每穴1~2顆。種子分佈實驗顯示改良之轉盤能達到70%左右之準確度，已大幅提高原本約20%之準確度；而多重播種率也從原本約80%下降至約30%，達到節省種子之目的。惟改良之轉盤其缺種率會隨工作速度提高，於9 km/h時缺種率約達7%。本研究仍建議當利用此播種裝置播種時，必須安裝種子擋板、掃除器以及擾動器。若以不整地每穴兩粒之方式播種紅豆，則可使用厚度3 mm的播種轉盤，而且工作速度維持於8 km/h以下可接近理想之播種密度。

The Adzuki bean is one of the important economic crops in the southern part of Taiwan between autumn and winter. The major places where Adzuki beans are planted are Kaohsiung and Pingtung, and most of them are sold in the domestic market in Taiwan. After Taiwan joined the WTO, the price of Adzuki beans became unsteady and the price has become higher than imported Adzuki beans. Therefore, the issue now is how to reduce cost and increase planting accuracy. For reducing the cost of seeds per area and manual operation, the sowing device in this study was operated according to the non-tillage dibbling method, with row space of 30 cm, seed space of 21 cm and two seeds in each group. The original sowing device tested and improved in this study was provided by a domestic agricultural machinery factory. The lab test focuses on seeding quantity, sowing accuracy, missing rate, and multiple sowing rate, and observes the effects of different discs: the original disc with a thickness of 7 mm and an improved disc with a thickness of 3 mm, at each working speed: 4 km/h, 5 km/h, 6 km/h, 7 km/h,8 km/h and 9 km/h. In the test, a belt was placed under the device to catch the beans, and an AC motor was used for driving the belt and the device. Gears between the belt and the motor allowed the sowing device to drop beans each time when the belt moved forward about 21 cm. After Adzuki beans were distributed on the whole belt, we measured the seeds spaces manually and calculated the results using MATLAB software. The result indicated that the installation of a retaining board, scraping brush and agitator are needed to allow this device to work normally. In the test of seeding quantity, the device with the original disc sowed excessive seeds. The seeds sowed by the improved disc corresponded more closely with the ideal total. However, when the working speed increased, the total seeds sowed deceased to 1~2 seeds in a group. The test of seeds distribution showed that the improved disc achieved better accuracy of up to 70%. Compared to the 20% of accuracy of original disc, the improved disc indeed had a better performance. Moreover, the test of the multiple sowing rate showed that multiple sowing could be reduce from 80% to 30%, making it possible to save more seeds. When the working speed reached 9 km/h, the missing rate with the improved disc reached 7%, however. Therefore, this study recommends the use of a retaining board, scraping brush and agitator when this device was driven. In addition, with a non-tillage two seeds dibbling method, the use of the improved disc with a thickness of 3 mm is a better choice, and if the working speed is kept under 8 km/h, near ideal seed distribution conditions can be obtained.