|By goGreen | June 28, 2012|
Wherever possible, introduce hedgerow strips of tree legumes every 6-7 m of about 1 m deep to provide green-leaf fertilizer for upland rice. Suggested tree legumes are Kakawati, Cassia spectabilis or ipil-ipil. Select a rice variety with a growth season well within the rainfall duration. The variety should mature by the time rainfall recedes.
Sow the rice seeds at the onset of the rain. A rainfall of 55-60 mm is desirable to ensure uniform and adequate plant population. Planting can be done either by broadcasting, dibbling, hilling or drilling.
- The land is prepared moist or dry. A modified broadcasting method is done by furrowing a harrowed field with a lithao. Seeds are broadcast uniformly and then a peg-toothed harow, kalmot is used to pass diagonally across the furrows.
- Thorough land preparation can effectively control weed population during the rice vegetative stage. Plow the field and leave it for a week to allow weeds to germinate. Harrow the field twice. Allow weed seeds to germinate. Then harrow for the third time to incorporate the weeds into the soil.
When hedgerows of tree legumes are tall, prune to hedges and leave the branches on the strips to allow leaves to decompose. Keep the field free from weeds for about 40-60 days after emergence to minimize yield losses. Competition for light, nutrients and soil moisture begins early.
- Hand-weeding is done if seeds were broadcast.
However, in modified broadcasting or row planting, mechanical weeding using a hoe can be done.
- In slopey areas where plowing is not possible, the use of crop residues as mulch can help control weed growth.
The leaves of legumes serve as fertilizer. If there is a large amount of biomass applied into the field at pruning time, it is not necessary to put chemical fertilizers. Using a legume-cereal rotation can also help improve fertility.
Pest control can be done as the need arises.
Integrated pest management (IPM) is highly recommended. As soon as the grains are ripe (about 80-85 percent is mature), harvest the crop. Increase productivity by intercropping and crop rotation. Legumes planted with rice or planted before or after rice can substantially improve yields with reduced external inputs.
FIG. 1. Start of the season
Plant alternating 2-3 rows of upland rice with a row of bush-type legume (preferably a short maturing one). About 16-20 kg legume and 50 kg of upland rice is needed to plant a hectare.
FIG. 1. Two months after
When the rice is at its late vegetative stage, the legume is harvested. The space occupied by the legume can be planted to corn or other crops like cassava or vegetables.
FIG. 1. Four to five months after
After the rice harvest, plant a short-duration legume crop where the rice was planted. If the field is free from weeds, the legume seed can be drilled or dibbled. Or, plant lablab or velvet bean following upland rice.
FIG. 1. Towards the dry months
Plant legumes that cover the soil during the dry season. Good potential cover crops include rice bean, batao and velvet bean.
FIG. 1. Plant rice in strips during the onset of the rainy season.
FIG. 1. Before the crops are harvested, plant legume cover crop to protect the soil during summer.
FIG. 1. Plant the whole field with upland rice.
It is suggested that more than one variety of rice in one field should be planted to spread the risk from calamity.
FIG. 1. After the rice harvest, plant legumes.
If the rice was planted in rows and the field is free from weeds, the succeeding crop can be relayed one week before harvesting rice. Cowpea, mungbean and peanut may be planted.
FIG. 1. Corn can be planted just after the legumes in case there is still sufficient soil moisture.
FIG. 1. But if the soil moisture cannot support corn growth, a third crop of cover crop like rice bean or lablab is suggested.
SOURCE: Crops and Cropping Systems (IIRR, 1992, 43 p.)