Water and Land Management – Agriculture Science | AG | notes
Wheat is number one cereal crop of the world on the basis of both the yield and area coverage. It is a major staple food grain for the peoples in the world. It is third cereals crop of Nepal after rice and maize. Wheat is less susceptible to disease and insect pest as compared to that of other cereals and oilseed and hence there is less risk of crop failure
Wheat is more nutritious as compared to that of rice and maize. It contains 11.8% protein, 1.5-2% minerals, 1.5-2% fat, 60-83% carbohydrates, 1-5-2% crude fibre.
The center of origin of what is believed to be South-western Asia.
Well-drained loams and clayey loams are considered the best soil for wheat cultivation. However, a good crop of wheat can be raised in sandy loams and black soils also. Heavy and black soils are considered best for durum wheat whereas aestivum wheat is grown in all most all type of soils. The soil should have moderate water holding capacity with a pH range of 6.6 to 7.3 for successful cultivation
Wheat is the cool loving crop. It can be grown successfully in tropical, subtropical and temperate climate as well. It can tolerate very cold climate and even the snow during early age of growth. Wheat is cultivated up to an altitude of 2800m from the MSL. It is cultivated as a winter season crop in Terai and Mid-hill regions of Nepal. While it is planted during autumn and harvested before the starting of severing cold in dry temperate regions having am altitude above 2200m from the MSL.
The optimum temperature for seed germination ranges between 20-250c. While best tillering occurs at the temperature range of 15-250c. During ripening phase the ideal temperature range is 14-150c. A higher temperature range above 250c accelerates the maturity process which may lead shriveling of the gains.
5. Cropping patterns/crop rotation
i) Rice-Wheat-Maize/summer vegetables.
C. High hill
6. Recommended cultivars
i) For Terai- UP 262, Nepal 297
ii) For Terai, Foothill and the valley up to an elevation of 1000m from MSL-B.L 1022, B.L. 1135, Bhirkuti.
iii) For Terai, Foothill and the region up to an elevation of 500m from MSL-Aditya, N.L 971.
iv) For Mid hill and high hill-Annapurna 4, WK 1204.
7. Land Preparation
– Wheat crops require a well-pulverized but compact seedbed for good and uniform germination.
– The field should be plowed 3-4 times, repeated harrowing, cultivation and planking are done before sowing for raising a good crop of wheat.
– Very timely cultivation of field is essential to conserve the soil moisture under rainfed condition.
– For the irrigated crop, the land is given a pre-sowing irrigation followed by cultivation and planking to prepare a fine well-pulverized seedbed.
– Recently zero-tillage and minimal tillage practices are adopted in order to conserve soil moisture under rainfed condition.
8. Manure and fertilizers
- Well decomposed FYM or compost should be applied @ 10-15mt/ha 5-6 weeks before wheat sowing either in rainfed or irrigated wheat field.
- For the higher yield following does of chemical fertilizer is essential. Under irrigated condition 100 kg N, 50 kg P, and 50 kg K per ha is applied. The whole amount of phosphorus and potash and half amount of nitrogen should be applied during final land preparation and remaining does of nitrogen should be applied at the first irrigation.
- Under rain fed condition 60 kg N, 40kg P, and 25kg K per ha is applied during the final land preparation.
9. Time of sowing
Optimum time of wheat depends on varietal characteristics. The early variety needs early sowing and late varieties are sown 15-20 days later on the early varieties. The optimum time of wheat sowing is second fort-night Kartik to second for-night of Mangsir.
10. Seed rate and Spacing
– Amount of seeds depending on their size, germination percentage, the method of showing, varieties etc. In general 100kg of seeds will be enough for a hectare of land. However, the varieties having larger grain size like Sonalika and UP 2425 need 110-125kg of seeds for a hectare of land. Wheat is sown 20-22cm apart in line and 5-7 apart from the plant.
11. Method and depth of sowing
For the better germination, the semi-dwarf cultivars are planed at a depth of 5-6 cm and the dwarf varieties at 4 cm. In case of late sowing, the seed should be planted be planted at a depth of 3-4 cm. Different methods of planting are adopted which are as follows:
i. Broadcasting- In this method seeds are sown uniformly by hand, the land is plowed and planked to cover the seed.
ii. Planting behind furrow-seeds is sown in an open furrow made by the indigenous plow. The seeds sown in the previous furrow is covered by next furrow.
iii. Seeding with the help of seed drill machine-Either a tractor or bullock drawn seed drill machine are used for seed sowing. The seed sowing with seed-drill machine maintain the uniform depth of seed and fertilizer and gives more uniform stand and early emergence of vigorous seedlings.
12. Water Management
Wheat sown under irrigated condition require 4-6 irrigation, depending on the soil and weather. Heavy deep soil with good water holding capacity may require 3-4 irrigation, while light sandy soil requires 6-8 lighter irrigation. Irrigation should be given during different critical stages of growth.
- Crown root – inititation stage (CRI stage) – 20 – 22 DAS
- Jointing stage – 35 – 40 DAS.
- Tillering stage – 50 – 60 DAS
- Flowering stage – 75 – 80 DAS
- Milking stage – 90- 95 DAS
- Grain filling stage – 100 – 105 DAS
Among different critical stages crown root initiation, booting stage, and milk stage are more critical. So the number of irrigation depends on the amount of water availability. (a) If water is available for only one irrigation, It should be applied at VRI stage.(b0 if water is available for two irrigation the first irrigation. (c) If water is available for three irrigation, the first irrigation should be given at CRI stage followed by
13. Intercultural operation
Keeping weeds under controls is very crucial for achieving high yield levels. Maximum damage is caused by weeds during the early growth stage of the plant. Several methods can be employed to control the weeds. Hoeing should be done after first and second irrigation with a hand spade or button which helps to remove the crust and destroy the weeds.