THE STUDY ON WATER BALANCE OF OILSEED CROPS IN THE NORTHERN THAILAND II: WATER BALANCE OF SUNFLOWER UNDER RAINFED CONDITION
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Abstract
The study was conducted under upland rainfed condition at the Mae Hia upland rainfed experimental farm during September to December 1987. The 15-15-15 fertilizer was incorporated to the soil before planting with the rate of 200 kg ha-1. Sunflower seeds (Hy-sun # 33) were drilled with plant spacing 25 x 75 cm. Ammonium sulfate and Borax were applied at 3 WAE with the rate of 450 and 12 kg ha-1 respectively. After 3 WAE, soil moisture content was weekly measured at different depths throughout the growing season. At the same time, plant samples were also taken to determine the plant height, LAI, total dry weight, and finally the grain yield. Two drainage type lysimeters were installed in the experimental plot in order to measure the water use of the sunflower crop. Agrometeorological data were recorded to calculate the crop water requirement.
The results shown that the total water used of the sunflower crop throughout the growing season was 273.7 mm while the amount of rainfall was 395.2 mm. The highest values of water used as well as and Kc were occurred during the flowering stage. The maximun values of and Kc were 4.6 mm day and 1.4, respectively. WUE based on grain yield was 0.63 kg m-3 or 1.6 m3 kg-1. Soil moisture content was sharply decreased after 3 WAE and approached the PWP at the 8th WAE. The amount of soil moisture extraction during this period in the upper 60 cm depth was about 0.80 cm3 cm-3. However, soil moisture content was recharged by rainfall in the 9th WAE and increased to the FC in the shallower depth. Then the soil moisture content was slightly decreased until the harvesting time. The amount of soil moisture uptake during this late period was about 0.29 cm3 cm-3 For crop growth, plant height was sharply increased during the vegetative stage and tended to be constant after the flowering stage. Leaf area index (LAI) and dry weight were moderately increased during the early stage of growth and sharply increased during the flowering stage. The maximum value of LAI was found to be 5.0 at the late flowering period and then starting to decline but the dry weight was still increased until the harvesting time. For the grain yield, it was recored at 2,146.3 kg ha-1
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References
Black, C.R., Tang D.Y., Ong C.K., Solon, A. and Simmonds, L.P. (1985). Effects of soil moisture stress on the water relations and water use of groundnut stands. New phytol. 100: 313-328.
Doorenbos, J. and Kassem, A.H. (1979). Yield response to water. FAO Irri. Drain. Paper # 33. FAO, Rome, Italy.
Doorenbos, J. and Pruitt, W.O. (1977). Guidelines for predicting crop water requirements. FAO Irri. Drain. Paper # 24. FAO, Rome, Italy.
Frere, M. and Popov, G.F. (1979). Agrometeorological crop monitoring and forcasting. FAO, Rome, Italy.
Gregory, P.J., Lake, J.V. and Rose, D.A. (1987). Root development and function. Cambridge University Press. Cambridge, UK.
Klodpeng, T., Sukasame, C. and Nimmalungkul, C. (1985). Rooting depth and rooting density of some upland crops under rainfed condition. Final Report Submitted to the ACNARP-THAILAND Project.
Klodpeng, T. and Morris R.A. (1984). Drainage of a Tropaqualf before and after water extraction by a crop. Soil Sci. Soc. Am. J. 48: 632-635.
Lomas, J., Schlesinger, E. and Lewis, J. (1974). Effect of environmental and crop factors on the evapotranspiration rate and water use efficiency of maize. Agric. Met. 13: 239-251.
Penman, H.L. (1956). Evaporation-An introductory survey. Neth. J. Agric. Sci. 4: 9 29.
Sukkasem, S., Manajuti, D. and Sukasame, C. (1985). The use of agrometeorological data for estimating water requiremants of upland rainfed crops in the upper northern Thailand. Final Report Submitted to the ACNARP THAILAND Project.
