by Dr. J.N. Daniel
The merits of the System of Rice Intensification (SRI) are highlighted extensively in contemporary literature. Many aspects of SRI, such as the use of organic matter, traditional rice varieties and non-flooding of fields are appealing to small farmers operating under resource-limited conditions. Enthused by these favourable attributes, BAIF Development Research Foundation in India experimented with SRI in its rural development project areas of Gujarat and Maharashtra states. This initiative saw tribal farmers growing rice with the SRI method in small plots in parts of their rice fields. The traditional method of cultivation is to grow rice on puddled soil in terraced plots. Rice is the staple food of these marginal farmers and the rice produced, usually in the range of 1.0-2.0 tons per ha, was primarily for home consumption. Cultivation was almost totally dependent on monsoon rains and the use of improved varietes and chemical inputs is not uncommon in recent years.
The performance of rice in the SRI plots was generally in agreement with positive attributes such as profuse tillering and dense rooting, which are highlighted in literature. SRI appears promising, but certain practical difficulties may constrain its rapid diffusion among farmers in the project areas where it was tried by BAIF. The aim of this paper is to share these observations with those who are in the forefront of promoting and further evolving this method of rice cultivation.
Seedling age at planting
The traditional practice of tribal communities in the project area is to sterilise the nursery bed by spreading a layer of biomass and burning it. Although each farmer burns only a small quantity of biomass, the total loss for the entire area taken together is substantial. In such a situation, planting single seedlings that are 10-12 days old is advantageous because the nursery can be a tray or a small plot in the kitchen garden.
Although transplanting four-week old seedlings is the traditional practice, heavy rains may force a delay by another week or two at times. In SRI, a farmer may start the nursery expecting to transplant on a particular day; but a few days of continuous rains around the designated day would render the field unsuitable and the seedlings would have become too old by the time conditions improve. The rainfall during the months of June and July, when land preparation and crop establishement operations are done, can exceed 1000 mm in the project area. Unlike in irrigated cultivation, rainfed rice requires greater flexibility in seedling age at planting, which is not there in the SRI method.
Associated with timeliness of transplanting is the aspect of labour sharing by small communities. The demand on labour usually peaks at the time of transplanting and again at harvesting. The practice among the farming communities in the project area is to share the family labour for these two operations. There is greater flexibility in the present method as the seedlings at transplanting are 25-35 days old. This age difference of 10 days enables easier sharing of the family labour among neighbouring farmers. The SRI requirement of 10-12 day old seedlings means less flexibility with regard to age as the range is only two days. This situation is further aggravated by the need to transplant single seedlings, which is laborious and time consuming.
Water management
SRI requires maintaining the field under saturated conditions immediately after transplanting and then having a wetting and drying cycle. Strictly following such a water management regime was found to be difficult under the rainfed conditions of the project area. In some farms, heavy rains immediately after transplanting uprooted or submerged the seedlings. This resulted in slow early establishment as well as gaps due to loss of seedlings. Ensuring regular wetting and drying cycles was also not possible under rainfed conditions. The levelling of the fields was not uniform in spite of the best efforts of the farmers. This resulted in seedlings in elevated spots wilting during the drying cycle and sometimes not recovering at all. Not that these cannot be overcome; mere sprinkling of water can revive the plants.
Organic manure
In general, the fertility of land of project participants is low. Introduction of practices such as soil conservation and organic manure application has resulted in some improvement. However, the soil fertility in most of the farms is below average. Organic matter available for use as manure is limited. Even households that have two head of cattle cannot produce more than 5.0 tons of manure whereas SRI would require the application of at least 10 t per ha. Besides the nutrient supply aspect, the organic matter content of the soil for water retention is another important consideration. Probably due to the low organic matter content, soil tended to dry up rapidly after it was wetted. Under rainfed conditions, if the next rains are not received in time, there is a likelihood of the crop experiencing a drought stress. In such situations, the traditional practice of flooding gives a few more days of cushoning in the form of standing water in the field.
Concluding Remarks
Transition from a traditional method to another is not always easy. Some changes required for SRI, such as the planting of single seedlings and the resultant increase in labour, can be overcome with practice. There are others where the difficulties pertain to resource conditions like water availability and soil fertility. Addressing these issues probably require trying out modifications to suit the local conditions.
Source : (http://www.baif.org.in/doc/Sustainable_Agriculture/LEISA-SRI.doc)
Source : (http://www.baif.org.in/doc/Sustainable_Agriculture/LEISA-SRI.doc)
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