| China is one of the countries with severe water shortage in the world .In North China, water resources per capita is only 404 m3. In Huantai county, as a high yield area in North China Plain, wheat production consumes a large amount of water resources duing to traditional management of cultivation needing irrigating time and again, On the base of the pilot study, demonstration and investigation, unsufficient irrigation and water saving techniques of winter wheat with high yield in the high yield area have been studied in this paper. The main results of the experiment as follows:1. Analysis of water consumption in different irrigation water treatment of winter wheat. Through the analysis of irrigating Lunong116 with different water amount, it is found that in the irrigated wheat field, the total water consumption climbs as the watering times and amount increase. The traditional way of irrigation supplies excessive water, resulting in water resources waste. When the times of irrigation being reduced and giving unsufficient irrigation the winter wheat can consume more soil water and rainfall. It is an important measure for the winter wheat to save water.2. Effects of the limited irrigation on the irrigated winter wheat groups dynamics and yield. The study shows that in the irrigated wheat field, by selecting wheat varieties with stronger drought tolerance and more spikes and reducing the times of irrigation from 5 or 3, it will help to control the dynamic development, restrict of vegetative growth and coordinate spikes with grain number and kernal weights to achieve high yield. Limited irrigation field is featured by dwarf straw, small leaf and compact stem with good property of straightness, resistance and large capacity of spikes.This is different from water-saving with output reduction or the traditional reduction or the traditonal concept of water-saving without output reduction. In the condition of this pilot study, the water consumption of winter wheat is 3213.4m2/hm2, the yield is 8130.0kg/hm2, the WUE is 2.53kg/hm2, with only one time irrigation, and the water consumption declines 1436.6m3/hm2, the yield is improved by 1155.0kg/hm2, and the water efficiency is increased by 1.03kg/hm2, compared with the field irrigated for 5 times.3. Research on water consumption law of water-saving irrigated winter wheat with high-yield. The water consumption of the three non-irrigation fields, referring to the sufficient irrigation field (irrigated for 6 times) have been studied. Average yield of the wheat in the three fields achieved 8123.1kg/hm2 by use of sufficient rainfall and 0-2m water soil.Compared with the fields irrigated for 6 times, the yield was improved by 18.76%. It showed that it was very important to make the best use of the rainfall and soil water for water-saving to achieve high yield of the winter wheat. Through the analysis we found that the per unit area yield of winter wheat was 8047.5kg/hm2, the economical water consumption was 2996.4m3/hm2, the water efficiency was 2.686kg/m3. This economical water consumption was obviously lower than the wheat water requirements estimating by Penman Formula and the results of other studies. The water efficiency was also higher than 2.32kg/hm2 of the developed country. Researching on the fields of enough moisture and sowing once in the spring of 2005-2006, it was found that the water consumption in the stage of winter wheat was lower at both sides and higher in the middle. The significantly lower declined water consumption was different from the general field in the stage of early growth of winter wheat .The mode conficient was only 28.89%. The water consumption raised from heading to the stage of mid and late filling, the mode conficient was 44.19%. The peak of the water demand intensity also appeared in this stage. In recent years, a comprehensive analysis of recent years showed that dividing the soil water supplying into seedling water layer (0-60cm), the mid-water layer (60-140cm), the post-water-layer (140-230cm) and the stable water layer(230-300cm) was more instructive in guiding the unsufficient irrigation and water saving winter wheat with high yield.4. Research on adaptation to limited irrigation of different winter wheat varieties. Based on pilot demonstrations in recent years, the drought resistance varieties-Lunong116 and Shijiazhuang 8 all post excellent performance in limited irrigation conditions. Their drought-tolerent index are 1. 093-1.2 while the drought resistance varies from level 2 to level 3.5. Winter wheat suitable for regulated deficit irrigation and the lower limit of soil moisture indicators. According to the surveys conducted in 2002-2003 and in 2005-2006, it is found that by selecting the strong drought-resistance winter wheat with limited irrigation, the lower limit of the soil moisture index from the jointing stage of wheat to maturity accounts for can be improve from 65%-70% to 55-65% of field capacity (moisture content 12.6%-14.9%), and the figure is 60% in the period of the stage of mid and late filling to maturity (moisture content 13.7%).6. Key period of irrigation, water saving and fertilization. Based on the practice and research in Huantai county in recent years, a conclusion can be reached that in well irrigation area, wheat field with medium fertility should be provided less water in prophase and anaphase and reasonably more water in metaphase. The key to achieve the goal of water-saving, high yield and anti-lodging lies in water control in the whole growth period of wheat which will ensure spikes. Apart from selecting drought resistant varieties and ensuring emergence complete, irrigation before and after the jointing period is the most important factor. The irrigation should be determined by seedling, moisture and precipitation, also it can be determined by water requirement, soil moisture and seedling, moisture. In the circumstance of limited irrigation, the organic fertilizer should be applied, and chemical fertilizers should be supplied during the irrigation, because the nutrient can infiltrate into the soil along with the water. Another important measure is that it can gain initiative for regulating and controlling irrigation during the whole growth period of wheat.7. Research on cultivation and management techniques of compensatory growth to adapt water shortage. The research shows that the best sowing time is from October 2 to October 10. It is obviously later than the traditional spring time. Under the circumstance of limited irrigation, to sow appropriately later can reduce water consumption of winter wheat. Appropriate later sowing, seeds should be increased in a bid to guarantee high yield and water saving. It is appropriate that rate of seeding to 120-135kg/hm2 and basic seedling to 2.40-2.70 million / hm2. Meanwhile, the seed dressing can promote the growth of the root. Post-spraying can help to withstand the dry hot wind. Seed dressing also have the impact of water saving with increasing output, which are the 3 remedial measures to adapt water deficit.8. Water-saving field irrigation technique. The study shows that two water pourings, short narrow furrow irrigation and every other folder furrow irrigation are the three technical measures of water-saving irrigation. It is the most popular and applicable irrigation measure derived from the practice of the masses. There are clear effects that it can drammtically decline the water consumption in the field. Also it is helpful to regulate deficit irrigation of winter wheat and to determine appropriate critical period for irrigation.9. Cultivation techniques of water-saving and high-yeild winter wheat. The paper summarizes and analyzes indicators of unsufficient irrigation and water saving winter wheat with high yield such as suitable varieties, collective dynamics, fertilizer, irrigation and appropriate time of planting, seeding rate and so on.
|
PDF Full Text Request