Bradbrook - 2012 - Rice Farming complete with methods to increase ric

More documents

Recommendations

Info

anywhere from 25 to 40 days depending on the variety. The grains are considered to have reached maturity and be ready for harvest when they have turned golden brown and are hard and opaque. At this stage, the leaves start to decay and lose their color. The developing grains are susceptible to attack from sucking insects in the early stages and birds and rats in the later stages. They are also sensitive to changes in environmental conditions. Grain filling (during milk and dough stages) is the process whereby starch and protein accumulate in the grain. This process is greatly hastened when the ambient temperature increases, resulting in partially filled grains containing undeveloped starch granules. On the other hand, low temperatures will lengthen the grain filling period; a significant incidence of frost will cause the entire ripening process to stop altogether. Light intensity is another factor that affects grain filling. Carbohydrates are synthesized during photosynthesis in the leaves and delivered to the grains. During periods of cloudy or rainy weather, the rate of photosynthesis decreases resulting in lower carbohydrate production and grain filling. Part 11: Cultural Management Practices 1. Water management a. Upland rice culture In developing countries, rice plants grown under upland conditions are completely dependent on rainfall for water. In developed countries, irrigation water may be made available to the field. In both cases, it is important to ensure that the soil is moist but not flooded; therefore, a good drainage system must be constructed to ensure good plant growth. Flooding during the vegetative stage results in poor tillering; during the ripening stage, grain filling is affected resulting in poor grain quality. b. Lowland rice culture The largest amount of water usage during lowland rice production occurs during land preparation when the soil is flooded to facilitate easy plowing and harrowing. The action of breaking the soil surface results in significant water loss through percolation and seepage. It is therefore vital that land preparation be done as quickly as possible after flooding. Once the seeds have been sown or the seedlings transplanted, continuous supply of water on the field ensures good plant growth resulting in high yields. At the early
vegetative stage, water levels should be kept at a depth of about 3 cm. As the plant grows taller, the depth is increased to 5 cm. This level is kept through the reproductive and ripening stages until 10-15 days prior to the expected harvest date. Draining the field at this time hastens the ripening process, inhibits further uptake of nitrogen, and makes the field accessible during harvest. Water scarcity During the growth period, water may not always be available to the rice field. There are several reasons for this: lack of rainfall, decreasing water levels in reservoirs, pollution and contamination, salinization, breakdown in irrigation systems, and competition from urban development. The occurrence of one or more of the above events can greatly reduce yield and even destroy the entire crop. The International Rice Research Institute has come up with a method to deal with instances of water scarcity. The Alternate Wetting and Drying (AWD) method is a mitigating measure that addresses the issue of limited water availability. In this method, water is applied to the field a certain number of days after the disappearance of water on the soil surface. This can be anywhere from one to ten days. Using a “field water tube” inserted into the soil to measure how far under the surface the water has receded, the field is flooded to a 5 cm depth when the water level has gone down to 15 cm below the surface. This distance is referred to as Safe AWD because no apparent reduction in yield is observed at this level of water. Water conservation using this method is about 15%. If higher water savings is desired, water levels below Safe AWD may be tried (e.g. 20 cm, 25 cm, or 30 cm below the surface) as long as yields do not suffer. Thus, it may be necessary to experiment with the levels over several growing cycles to find the one that the rice variety being grown can tolerate. There are breeding programs in several countries that have developed lowland rice varieties that are able to grow in soils deprived of water. Such rice varieties are called “aerobic rice”. They have the same qualities as upland rice varieties in that they can be grown in soils lacking sufficient water, but they possess the superior characteristics of lowland rice in terms of yield potential. 2. Nutrient management a. Compost Adding compost to the rice field for incorporation into the soil at least two weeks before land preparation greatly improves soil quality. The compost can be made 30
Page 1 and 2: T he in form ation w ithin this boo
Page 7 and 8: Section 4: Post-harvest Processing
Page 9 and 10: Top 20 rice producing countries in
Page 11 and 12: ut does not experience long periods
Page 13 and 14: ainfall. During the ripening stage,
Page 15 and 16: small farmers and their families wh
Page 17 and 18: 3. Steps in land preparation 1 a. P
Page 19 and 20: point (i.e. >50m), it is advisable
Page 21 and 22: a. Genetically trae to its kind (of
Page 23 and 24: г c. Separate weed seeds and seeds
Page 25 and 26: ice seeds germinate with weed seeds
Page 27 and 28: г are planted just under the line
Page 29: potential, whereas in the latter, t
Page 33 and 34: г с. Macronutrients and their rol
Page 35 and 36: The soil naturally contains nutrien
Page 37 and 38: 1 zinc sulfate while still in the n
Page 39 and 40: In both upland and lowland rice cul
Page 41 and 42: Combating disease attack involves h
Page 43 and 44: í The best time to apply fungicide
Page 45 and 46: 7. The Economic Threshold The econo
Page 47 and 48: The pedal thresher is a hand-operat
Page 49 and 50: г I*
Page 51 and 52: establish themselves. Some common-s
Page 53 and 54: . Mechanical control Use traps to c
Page 55 and 56: 1. Claims o f SRI: a. Results in hi
Page 57 and 58: the genetic yield potential of the
Page 59 and 60: 2. Befare planting: a. Establish ta
Page 61 and 62: temperatures. Key Check: Phosphorus
Page 63 and 64: 2. Requires data-gathering skills:
Page 65 and 66: 1. Sun drying This drying method is
Page 67 and 68: ’Г of the milled rice. If any bi
Page 69 and 70: not commercially viable, b. Single
Page 71 and 72: 70
Page 73 and 74: production is typically lower than
Page 75 and 76: irrigation water is obtained from u
Page 77 and 78: 76
Page 79 and 80: 78
Page 81 and 82:
г http://www.irri.org/index.php?op
Page 83:
The information within this book wi
show all

Bradbrook - 2012 - Rice Farming complete with methods to increase ric

Create successful ePaper yourself

Delete template?

Save as template?