Definition of the Technology:
The Technique of using decomposed rice straw in household gardening is an effective soil improvement practice carried out by the local people. The decomposed rice straw helps to improve soil moisture, provides organic matters to the soil, which a cost- effective soil amendment practice, and results finally in increased crop yields.
Rice straw mulching was initiated locally in Daktaock-noi village, Dakchueng district in 2014 as a technique to improve the soil quality in household gardens. Previously the farmers used to apply animal manure (cow and buffalo excrement) to improve the soil fertility in the village’s vegetable gardens. However as a result many of them experienced an outbreak of pests such as root-knot nematode (Meloidogyne enterolobii) who damage the plant’s root, and aphids which also destroyed the vegetables plant’s leaves. This led to low productivity and an inferior quality of vegetables that could not be sold. The farmers therefore explored and experimented with new methods once they had made observations of the effect of leaving rice straw on the rice paddies or surrounding areas for a period of four to five months after the rice has been harvested in October. They noted that the soil in these areas became more fertile as the emerging new rice sprouts were healthy due to rice straw decay existing in the field. It illustrated that when a layer of rice straw is left on the surface of the field that this has a positive effect on the soil. For instance it enhances the soil’s moisture and there is an increase in organic matter resulting from the decomposed rice straw which improves the soil’s fertility.
The land users therefore started to store the rice straw in specific locations after the rice had been harvested. They stockpiled the rice straw in parts of the rice field that were water logged or more humid. This way the rice straw could absorb water and then be collected at a later stage. If the rice straw is not stored, it will dry out and be dispersed naturally by the wind.
Typically, there are two times in the year that the farmers become active in the production of compost from the rice straw. The first time is in October after the rice has been harvested when there is not a lot of rain. The second occasion takes place from January to February, which allows a period of 4-5 months for the rice straw to decay after it has been collected. The only raw materials that are needed for the production of rice straw compost are the actual decomposed rice straw and soil. The only essential equipment consists of a blade for the cutting of the rice straw, and then bags for the collection, as well as a hoe for the preparation of the plot to grow vegetables.
The rice straw compost production process begins with the collection of two bags (20 kg) of decomposed rice straw from the rice field, which should then be well mixed with one bag (10kg) of soil. This mixture should be applied directly onto the vegetable plots before sowing the seeds. After the application of the rice straw compost it was noted that the vegetables grow successfully without being disturbed by pests or insects. The soil gradually became darker which is an indicator of good soil fertility. Thereafter vegetable production increased and the farmers were also able to grow a greater variety of vegetables including scallion and coriander, which had previously not been possible. Currently, the local people are able to cultivate three crops per year which generates an additional source of income for the households.
Additionally the application of rice straw compost can help farmers adapt to climate change, particularly in periods of heavy rainfall. This is because areas where the soil’s surface has been covered with rice straw mulching are protected from surface run-off during heavy rain. Once the rice straw has been distributed over the vegetable patches it was noted that the root-knot nematode had decreased in numbers when they were found in the soil.
In general, the local people are satisfied with this technique as it only requires the input of labour in order to gather the rice straw, which farmers can do on their own rice fields with no additional costs involved.
The rice straw compost production process: Firstly collect the rice straw from the field after the rice has been harvested. The rice straw should be stockpiled in particular locations around the rice field where the floor is wet or more humid for a period of 4-5 months to let them gradually decompose.
These patches should be hoed to approximately a depth of 15 cm, then decomposed rice straw should be mixed with topsoil from the prepared vegetable patches for 10 cm thick and the patches have width of 1 m , length of 3 m. There should be a distance of 15 cm in each direction between the vegetable seedlings. Once the patches are covered with an approximately 5 cm layer of decomposed rice straw. The space between each of the vegetable patches should be approximately 20 cm, and the total area of the home garden is 25 m2.
Lao People's Democratic Republic
Region/ State/ Province: Xekong province
Further specification of location: Darktaork noy village, Darkchung district
Source: LaoCAT, NAFRI, MAF