In a pamphlet that discusses soil and water conservation, Ross S. Manglona, Dilip Nandwani, Lee Bowen, and Claus Bier of the Northern Marianas College-Cooperative Research, Extension & Education Service share farming methods that do not put a heavy burden on natural resources.
The study program was funded by a conservation innovation grant from the U.S. Department of Agriculture’s Natural Resources Conservation Service. Additional funding was also provided by Agriculture Development in the American Pacific.
Commercial farming was established in the Northern Marianas a long time ago. However, the local farming community has yet to adopt many of the methods in use throughout the contiguous United States. Many of the techniques used by local farmers include heavy tilling, manual weed pulling and surface irrigation.
These techniques are very labor intensive. Moreover, farming on bare soil promotes erosion and sediment runoff. The sediments eventually end up in the lagoon disturbing the growth of corals, if not killing them, and so depriving fish of food and hatching places. Thus, the islands might lose fishing grounds and income from the reef as tourist attractions.
NMC-CREES has been working with farmers on enhancing their agricultural profitability. This is done by considering the benefits of traditional and modern agricultural techniques with emphasis on soil and water resources. It intends to reduce soil erosion and water overuse by performing the following practices used on its experimental farm in As Perdido.
Contour farming. This uses tilling parallel to the contour lines of a hill. This slows down erosion through slowing down water runoff. Soil quality doesn’t deteriorate fast, and thus fertilizer-use can be minimized. It takes away the strain on groundwater levels and adds to water quality in general due to less fertilizers leaching into aquifers.
The use of hedge rows along the contour lines further improves contour farming. With hedge rows, erosion can be further reduced. Sediments that normally would be washed away are caught in the edges. Nutrients and minerals stay in the field.
Mulching. This means that the soil around the crops is covered. The covering can be done by plastic mulching foil, paper shreds or cuttings from vetiver grass. It doesn’t matter which material you use; what is important is that it reflects sunlight, water can permeate through it and that the material is slowly decomposing so you can simply till it into the soil after harvest.
The idea of mulching is to keep the soil around the crops covered. Weeds don’t get enough sunlight, saving the farmer the cost and labor of weeding. Additionally, the farm crops don’t have to compete for nutrients with weeds. More nutrients for the crops mean higher yields and profits for the farmer.
Mulching keeps the soil moist and regulates soil temperature. The ideal plastic mulch for the CNMI has a white, reflective surface. The best plastic mulch is not too UV resistant, so it decomposes faster. It should not hold longer than one-seeding harvesting cycle.
To apply the mulch, paper sheds or plant cuttings are simply spread around the crops. Plastic mulch can be applied with the help of a ridger,
The first step is to ridge the bed. Apply the mulch foil. A second run with the ridger, set to a larger working width, fixes the mulch on the ground. The last step is to sow the seeds or set the seedlings through precut holes. Different crops need different ways of mulching.
Organic mulching with paper shreds or plant cuttings is best for corn and string beans. Plastic mulch has the most advantages for tomatoes, okra, eggplant, peppers or melons.
The ideal way of using mulch is in combination with a micro-irrigation system. Mulching seems to be labor intensive, but it results in actual savings in the cost of manual weed pulling, herbicides and watering as well as a higher yield of crops.
For more information, call NMC-CREES at 234-5498 ext 1705 or visit the Web site at http://crees.org.
