- Slides: 29
Rice Farming (Intensive farming activity)
Rice cultivation • Rice is a major crop grown in most tropical and semi-tropical regions. Different systems of growing rice have evolved to suit specific environments and socioeconomic conditions. • With wet-rice cultivation, seeds are planted out by hand in rows in slightly drained, or puddled, fields. Throughout growing, water levels in paddy fields are kept to a few centimetres deep to prevent weed growth and ensure there's enough water for the plants to grow. This is done by either flooding during the rainy season, or by planting the rice in naturally swampy areas, or by irrigating using a series of canals or wells. Fields are sometimes temporarily drained for weeding and fertilising.
• Harvesting Grains are harvested before they are fully mature, about 30 days after the rice plants have flowered. The rice plants are cut halfway up the stem and either allowed to dry in the field or bundled for processing. The commonest method is harvesting by hand, which is very labour intensive. A sickle is used. Mechanical harvesters are becoming more popular. • Processing Harvested grains are threshed to separate the grain from the stalk and enclosing husk. This is usually done by bashing bundles of rice stems on a stone or other hard platform, or using animals to trample on the stems. Threshing machines are becoming more popular.
Case Study 1 : Rice farming in South China is the largest supplier in the world. The rice distribution in China is divided into 6 districts. About 91% of rice cultivation area is distributed in the 3 districts of southern China.
Favourable Factors for Developing Intensive Rice Cultivation in South China PHYSICAL FACTORS Climate a. Tropical monsoon climate High solar energy input and high precipitation (annual: 2000 -3000 mm) in summer Favour plant growth , especially the tropical crops e. g. rice b. Warm temperature Long growing season Double-cropping is possible Soil and drainage a. Rich alluvial clayey soil is found in Xi Jiang Basin and on Zhu Jiang Delta b. Impermeable subsoil suitable for rice cultivation Relief High mountains sheltering cold wind in winter
CULTURAL FACTORS Labour supply Abundant and cheap manual labour supply Market Large demand for rice from the dense population History Long history on farming and good experience on farming rice
Farming constraints in South China Farming constraints Measures to overcome the constraints PHYSICAL CONSTRAINTS (1) Land Shortage of arable land ∵lowland is limited and hilly landscape (2) large rural population great population pressure on land ∴- field size are small - farm production is small - large farming machinery cannot be used a. ↑arable land through: (1) terracing on hill slopes (2) reclaiming marginal land b. practising intensive cultivation c. improve farming efficiency by using small machineries e. g. rice transplanters Effectiveness: --farmland is increased --farm productivity is increased --but it is difficult to irrigate in upper terraced slopes
(2) Climate a. typhoons, heavy rainfall , strong winds in summer cause great damage to the crop of rice b. low-lying farmlands suffer from flooding c. drought is common in autumn and winter a. Planting of short-stalk rice which can stand heavy rain and strong winds b. Planting of windbreaks c. Carrying out large-scale irrigation projects Water is channeled from rivers to the fields Reservoirs are built to store eater for irrigation Effectiveness: --losses and damage to rice are reduced --amount of irrigated farmland is increased --water resources are conserved --farm productivity is increased
(3) Soil a. thin and infertile in the hilly areas b. soil fertility decrease rapidly due to intensive cultivation Use of chemical fertilizer (4) Pests and diseases a. Use of pesticides b. New disease-resistant rice species are cultivated Effectiveness: --so more intensive use of land is possible --farm productivity is increased Effectiveness: --pests and diseases are under control
CULTURAL CONSTRAINTS (1) Farming technology Low level of farming technology ∵ little capital farming efficiency remains relatively low (2) Government’s influence The types of crops to be produced have been strictly controlled by the government a. More small-scale farm machineries are now in use b. Researches on farming techniques are carried out by the Central Government Effectiveness: --farm productivity is increased With the introduction of responsibility system, farmers have greater freedom in deciding the types of crops to be grown
(3) Transport poor transport network More efficient transport links have been extended from urban areas to rural villages Effectiveness: -- more new farming techniques are brought to farmers (4) Education Most farmers are illiterate which hinder the growth of farm modernization (5) Market - for local market only - few international market Provide more education to the existing farmers and their next generation Effectiveness: --farm productivity is increased
Terrace rice fields in Yunnan Province, China
News about Rice in China has developed an easy-to-grow rice variety, which scientists say will eventually relieve millions of rice growers around the world from the backbreaking labor of planting rice, seedlings by hand alleviate farm water shortages in China. Chen Dazhou, director of the Rice Institute of Jiangxi Province, said the rice, nicknamed "idiot rice", will grow for several consecutive years after harvesting, eliminating the most labor-intensive job of planting seedling by hand. … The other issue is the poor capacity of rice to withstand cold. Chinese scientists have made marked progress in their search for rice genes capable of withstanding cold. …
The wild rice, which was found on 0. 3 hectares of the reserve in a State protected reserve, can stand cold weather of up to minus 12. 8 ℃, far outstripping other varieties of rice with strong cold and aridity resistance. Chinese scientists had been able to achieve asexual reproduction of rice with powerful cold-resistant genes, and overcome the difficulty in retaining the advantage from crossbreeding. The director described the rice as an unusually rare variety. Compared with conventional methods of growing rice, the new variety saves a lot of seeds, fertilizer, water and labor, cutting losses of water and soil erosion. The new variety saves 15 to 75 tons of water per ha, an attractive point for China, a country short of water and farm labor. Many rural families are short of hands in rice-growing seasons as young and middle-aged farmers have left their patchy farmland for jobs in cities. …
Growing Rice Jan Feb Mar Apr May Jun Jul Aug Sep 1 st harvest 2 nd harvest seedling transplanting growing harvesting Oct Nov Dec
Case Study 2 : Rice farming in India • Rice is the main cereal for majority population in India. • The demand for rice is growing with everincreasing population. • Rice is water intensive crop. More than 70 percent of the country’s ground and surface water is being used for agriculture
• Tamil Nadu – India's southernmost state – About 2 million hectares of rice is grown • mostly under irrigation, with an average yield of 5 t/ha – Average rice productivity is the highest in the country
• Tamil Nadu
• But, water shortages are becoming increasingly severe, and overall production has decreased in recent years……
• So, The System of Rice Intensification (SRI), was introduced to Tamil Nadu in 2001. – There are visible results that SRI farmers achieve.
SRI • Younger seedlings – conventional rice production: farmers are recommended to transplant seedlings at between 25 and 30 days. – SRI: advised to use 9 -12 day old seedlings • young seedlings are strong enough to withstand transplanting • they are also in a better condition to do so.
• Nursery – Farmers in Tamil Nadu usually have a specific field earmarked for a nursery • To receive more manure. – farmers often use seed rates which are 3 to 5 times higher • = seedlings are densely spaced less healthy. – SRI : 20 x 20 cm spacing and only one seedling per hill • The wider spacing and single seedling per hill drastically reduces the seed requirements in the nursery, with only 7. 5 kg of seed required per hectare instead of 20 kg. • farmers use far fewer seedlings.
Establishing a modified mat nursery for rice : http: //hk. youtube. com/w atch? v=CLS 2 Wv. Mo. DLc Nurseries can be smaller as less seedlings are needed under SRI practices.
• Plant density – In Tamil Nadu planting distances of 15 x 10 cm and of 20 x 10 cm are conventionally recommended for short and long duration rice respectively. These recommendations suggest a density of two or three seedlings per hill, although farmers generally plant 4 to 6 seedlings. – SRI : leave wider spaces between the hills, and plant a single seedling in each. • wider spacing enables higher tillering rates (depending in both cases on the fertility of the soil). • The wider spacing also gives the seedlings a larger zone from which to draw their nutrients. • A spacing wider than 20 x 20 cm is appropriate if soil fertility is good.
• Weeder use – Different evaluations have shown that weeding is one of the most important factors in SRI. This represents a major change in rice cultivation, and has a noticeable effect on the growth of the plants. – Farmers in Tamil Nadu use two types of weeders. One is the rotary weeder, which is light (2 kg) and can therefore be used by women labourers. – The other model, the cono-weeder, is used with wider spacings. It weighs approximately 7 kg and is mostly suitable for use by men. – Large farms have also introduced motorised weeders, though these are only successful if the square planting and lines are perfect. – weeder use an 「earthing up」 action
• Shallow and intermittent irrigation – In Tamil Nadu, rice is grown in many different conditions, with water availability dictated by the monsoon rains. – The north east monsoon season (between October and December) – the main rice season in both irrigated and rainfed environments. – In conventional rice production in Tamil Nadu it is generally recommended to flood the field with a layer of water up to 5 cm deep – SRI: soil should remain as aerobic as possible. – Current practice among SRI farmers is to provide a water layer of up to 2. 5 cm after cracks develop in the surface of the soil up to the panicle initiation stage. This approach requires regular monitoring of the field, which is especially important in cascade irrigation areas and during the monsoon.
• Adoption of SRI by farmers – SRI is attractive to small and marginal farmers because of …… • the higher yields, the lower seed requirement and the relative ease of weed management.