On the steep slopes of Bac Ha commune, Lao Cai province, northern Vietnam, the move to switch maize fields that grow thinner with every rain over to agroforestry combining VH06 pears and red peanuts has entered its second year. In a demonstration by the international agroforestry research institute ICRAF, a figure of topsoil runoff dropping by an average of 46.7% has emerged. This design, which rebuilds soil and income at once on mountain slopes, has much to read both for buyers hunting for northern fruit in Japan-bound procurement and for Japanese origins holding poor hill-and-mountain fields.<\/p>\n
The setting is Coc Khai and Ban Pho villages in Bac Ha commune, Lao Cai province. On high-elevation land where monsoon downpours fall in bursts, farmers have long relied on maize monoculture. Cultivation that plants only maize on steeply sloped fields has the topsoil between the rows scraped away by rain with every harvest, surely shaving the next year's soil fertility. ICRAF researcher Pham Thanh Van explains the demonstration result that over the two-year effort \"topsoil runoff fell by an average of 46.7%.\" What the number shows is the simple but hard-to-budge fact that soil erosion can be curbed by cropping design rather than by sheer willpower.<\/p>\n
Len Van Quan of Coc Khai village speaks not only of income but of changes in the field itself. \"Not only has my income grown, but I feel that the soil of my family's swidden has become much better than before.\" On slopes, the recovery of soil fertility bounces straight back into the next crop's yield. Stopping erosion is a matter of the environment and, at the same time, a matter of management: how much you can earn the next year.<\/p>\n
The core of the switch is agroforestry: planting several crops in layers along the contour lines rather than against the slope. ICRAF's \"Restoring degraded land and building adaptive capacity to climate change\" project set as the axis fruit trees such as the dwarf VH06 pear, the yellow plum (man van, AFLi variety) and lotus mandarin (quyt sen) in Bac Ha. For the several years until the fruit trees bear, the fields are not left idle; short-cycle crops such as red peanuts, black beans and sweet potato are slotted between the plants.<\/p>\n
Le Van Liem of Coc Khai village speaks concretely of how to use this waiting time. \"While waiting for the plums and mandarins to bear, at home I intercrop black beans.\" Fruit trees are the pillar a few years out, intercrops are this year's cash - the idea is to crush, at once, both the income gap and the period of bare ground by layering crops with different roles on the same slope. It disperses a one-legged maize field along both the time axis and the space axis.<\/p>\n
The fruit trees' returns are still at the launch stage. The VH06 pear of Ly Seo Dung in Ban Pho village has only just begun to bear and stays at income of \"a little over 8 million VND a year (about 46,000 yen).\" Seen in isolation, that is small. But the lift from the short-cycle crops running at the same time is working. Red peanuts, switched to contour planting, were recorded as yielding 20-25% more than the old method. With less erosion and topsoil staying put, rooting and pod set improved. Across the whole project, 25,000 superior seedlings have been distributed, spreading to an area of over 100 ha, 13 communes and 348 households.<\/p>\n