Study on Wide and Narrow Double-row Ridging Cultivation Mode and Mechanized Planting of Cassava

【Objective】 Cassava is an important starch and energy crop in China. At present, its production mainly relies on manual labor, which causes high production cost and low economic profit. The cassava harvesters developed in recent years seldom matched with equal row spacing cultivation mode adopted currently. While harvesting with these harvesters, tractor wheels inevitably crush on cassava rows and cassava roots are destroyed, which resulting in a root loss rate of up to 17%.【Method】In order to avoid row crushing and increase root harvest rate, according to the requirements of mechanized harvesting and the wheel size of a 66.2 kW tractor, a cultivation mode of wide and narrow double-row ridging planting was designed with wide row spacing being 120 cm, narrow row spacing being 60 cm, and ridge height being 25-30 cm. A cassava ridger and a cassava combined planter matching the planting mode were developed, and adaptability experiments were carried out in different producing areas including Guangdong, Hainan, Guangxi and Yunnan.【Result】With the wide and narrow double-row ridging cultivation mode, the ridging efficiency was 0.6-0.8 hm2/h, the planting efficiency was about 0.6-0.7 ha/h, the efficiency of mechanized planting was 23 times higher than that of manual planting and the cost of mechanized planting was only 50% of manual planting. The cassava yield(under mechanized planting) was 33-42 t/hm2. Mechanized harvesting with this planting mode could effectively avoid row crushing and significantly reduce root broken rate, with the loss rate of less than 5%.【Conclusion】The study showed that the wide and narrow double-row ridging cultivation mode can be well suited to mechanized planting and harvesting and promote the high integration of agricultural machinery and agronomy.