Rice Production: Chapter 6 - Methods of stand establishment

Introduction

Two methods of stand establishment - broadcast sowing and transplanting - are widely practiced in Sierra Leone. This chapter describes both methods and includes summaries of the advantages and disadvantages of each.

I. Broadcast Sowing

a) Traditional: 

Most traditional upland farms in Sierra Leone are sown by Broadcasting of ungerminated or germinated seed at the beginning of the rainy season Seed is scattered by hand at a rate of 80-120 kg/ha in soil that has been burned over, cleared, and turned with the native hoe. Usually kitchen crops are mixed in with the rice - beans, millet, sorghum, tomatoes, corn, okra, sesame pumpkin, and watermelon are the preferred varieties. The seed is covered by hoe, rake, or spike-tooth harrow. Traditional broadcast sowing i fast and labor-saving, making it particularly well suited to large upland farms. However, traditional broadcast sowing has several marked disadvantages:

- germination rates are often uneven, due to the reliance on rain
- heavy rains can dislodge and wash away seeds, resulting in uneven seedling stands
- seeds are exposed to rat and bird attack
- broadcast seedlings do not compete favorably with woods
- broadcast seedlings are difficult to weed

b) Improved (Direct Seeding):

In area., where irrigation water is plentiful and easily controlled direct seeding is extensively used with excellent results. The availability of water is essential because relatively deep water discourages the growth of grassy weeds. Effective water control ensures that the plots can be drained during the seedling establishment phase.

Two methods of direct seeding are most commons broadcasting directly onto soil that has been prepared thoroughly by plowing and several harrowings, or broadcasting onto standing water (usually from airplanes). Ungerminated or pregerminated seed may be used. The main advantage of improved direct seeding is the low labor cost. The several operations of nursing -preparling seedbeds, watering, uprooting, and transporting of seedlings - are completely eliminated. In areas in which labor costs are high, direct seeding can cut production costs significantly. Nevertheless there are various disadvantages:

- exposure to rats and birds
- weed control is difficult without the use of herbicides

II. Transplanting

a) Hand Transplanting

Hand transplanting is the most widely practiced method of stand establishment in small-scale, labor-intensive (wet) farming systems throughout the world. Seedlings are nursed in seedbeds and then uprooted for transplanting into lowland puddled soil.

The major advantage of transplanting is that the seedlings gain a significant head start over weeds. However, transplanted seedlings tend to grow more slowly than direct-seeded plants because of the root damage suffered during uprooting. Furthermore, hand transplanting is extremely labor-intensive.

Hand transplanting is done either randomly or in rows. Random transplanting, traditional in some parts of Africa and most of Asia, is significantly faster, but the distance between seedlings is not uniform, and no definite aligning pattern is followed. Consequently, randomly-transplanted stands are often uneven, difficult to weed (the use of mechanical row weeders can be ruled out), and difficult to walk around in (e.g. for purposes of broadcasting fertilizer). Straight row transplanting is done wit.. the use of planting guides (usually a rope knotted at regular intervals, or a planting stick) Straight row planting is time-consuming, but it offers several advantages: optimum spacing is possible, the row weeder can be used, and the stand of plants is easy to walk around in during fertilizer and/or pesticide application.

Transplanted seedlings should not be planted too deep (1/2" -1" is best), since tillering is discouraged when the lowermost internodes become completely buried. Never thrust seedlings deep into the soil in order to make them stand upright. For best results, barely cover the roots - the seedlings will right themselves within a day or two, and in the long run they will tiller more vigorously and yield better.

Plant spacing is an important factor and will vary depending on variety, soil fertility, and season of planting. Generally, rice plants are spaced more widely in the wet than in the dry season because in the wet season they tend to grow more profuse leaves and tillers, thus increasing mutual shading. As a general rule, encourage the farmer to plant 3-4 seedlings/hill (except with very low-tillering varieties, which should be planted at a rate of 5-6 seedlings/hill). Space the hills 8"X8" during the wet season, 6"X6" during the dry season. But be prepared to modify these general recommendations to fit Particular situations.

Notes It is sometimes difficult to decide whether or not to advise a farmer to plant in rows. In theory row planting is preferable to random planting, but in certain situations the extra time required will not always yield better results (e.g. if the farmer does not own a row weeder and will not be walking around in the rice to fertilize). Generally farmers will be reluctant to spend the extra time to plant in rows, and the extension agent must be careful not to alienate them by a rigid insistence that things be done "by the book." Often the best approach is to experiments offer to help plant a few plots in rows, and then let the individual farmers decide whether or not the additional labor investment pays off in terms of a more uniform, easily-weeded, and higher-yielding stand of plants.

b) Broadlings

Broadling is a method of stand establishment practiced in parts of Asia where rice paddies are extremely boggy, making it difficult to walk in them. Nursed seedlings are thrown randomly into the puddled soil from the edges of the paddies. Much practice is required before uniform stands can be achieved on a consistent basis. The seedlings establish themselves quickly, since the roots do not get buried deep in the soil. Although broadling can be effective in some very specialized farming eco-systems, the technique requires smaller plots than are found ordinarily.