Effects Of Cultivation Conditions On Crop Growth And Root Hydraulic Lift

With the contradiction between water supply and demand is increasingly aggravating, all over the world regard the water saving agriculture and the ecological agriculture as the main measures for sustainable development. However, the cost of existing irrigation technology was high and the efficiency was low, nearly 40% of the irrigation water lost through evaporation (FAO, 2002). Therefore, certain measures can be taken by advantage of the growth of crop physiological characteristics to saving water. The hydraulic lift to make plant roots use deep soil moisture better, which can have a strong survival and productivity in dry conditions and save irrigation water. The results show that the deep-rooted plants in plant communities can use the root system to enhance the water supply to plants thus promoting the competitiveness in ecosystem evolution, especially shallow-rooted plant. Through the root system hydraulic lift, deep-rooted plants can increasing shallow root activity, thereby enhancing the root system efficiency and reduce carbon consumption and increased access to soil resources, increase crop productivity and ecological networks primary productivity. But how to apply the results to agro-ecosystems, to study agricultural ecosystems and root hydraulic lift irrigation function, had not received due attention. Therefore, study of hydraulic lift, combined with effective use of crop nutrients and energy of the loess zone "soil reservoir", is the core of agricultural in the Loess Plateau, and is direct and important significance for the development of water-saving agriculture. And the loess areas of the agro-ecosystem regulation of water / nutrient spatial mismatch of contradictions, full mobilization of the deep water and nutrient efficiency in order to maintain the upper shallow roots strategies for survival and activity have a certain theoretical significance.This paper, based on the scientific hypothesis of "in the shallow soil fertilization under drought stress by affecting the root system and will affect the root hydraulic lift, hydraulic lift and root growth period varies" and the scientific questions, "deep-root crop root hydraulic lift is for shallow-rooted crops affected by drought stress in biological irrigation device " winter wheat variety Xiaoyan 22, corn Zhengdan958 and soybean varieties Jindou 19 as test material, using self-made compartment soil culture device, using time domain reflectometry (TDR) to control and observed the soil moisture of the upper and lower layer to study the effect of different levels of water stress and fertilization on winter wheat and whole growth period of roots for water use efficiency; and the effect of different planting methods on corn / soybean growth and enhance the role of water. Main research conclusions as fallowing:1) The winter wheat plant height, grain weight, grain number, upper biomass, harvest index and other physiological indicators different treatment of showed the same regularity. Overall performance was, compared with CK and N treatment, NP treatment and P treatment demonstrate advantages. NP grain handling up to 1393, the lowest was 794.33, 2.39 times than N treatment, CK handling 2.42. On grain weight, NP treated as CK Ho N deal 3.25 times and 3.18 times the difference between treatments was significant.2) Experiment confirmed the upper and lower soil water potential difference is the root, there are some hydraulic lift occurred as essential prerequisite. Xiaoyan 22 winter wheat on the soil under the wet-dry conditions, moisture control (ie, upper and lower soil water potential difference when there are some) are obvious root hydraulic lift, up and down in the dry soil, the upper and lower control conditions were almost wet water not observed in root hydraulic lift.3) With the growth of winter wheat roots provide water to promote a gradual increase in applied N and root hydraulic lift CK, both get peak in the flowering stage, then began to decline in different degrees, while the application of NP and P treatment facilities in the flowering root hydraulic lift and grain filling stage has been strong, and get highest peak. Tests under different dry-wet soil moisture conditions, winter wheat in different root hydraulic lift, M roots under water treatment conditions were significantly higher than the total for water D water treatments. NP treatment provided under the M water treatment water treatment is 1.66 times than D, and P, CK and N treatments were 2.19,1.99 and 1.24 times. M and D in the two water conditions, NP fertilizer pot for water treatment total winter wheat were the highest 1820.3g and 1099.0g, single application of P treatment were 1.09 and 1.44 times, CK 253 and 3.03-fold, and the single application of N treatment and 2.92 times 3.90 times.4) In addition to CK moisture conditions, the test performance of winter wheat water consumption for the H water treatment> M water treatment> D water treatment. Look from different fertilizer, applied in general NP showed the highest water consumption, followed by applied P treatment, N treatment and CK Shih quite. But with the total water consumption in contrast, the dry under wet soil moisture (M and D) than the overall wet processing (H) ,hais the high WUE for winter wheat, but the difference was not significant. View from a different fertilizer, NP processing mode and processing mode, P was significantly and higher of WUE than the N treatment patterns and CK treatment. NP dealing with the average WUE was 1.38g / L, CK processing mode is 1.37 times, 1.68 times that N processing.5) The promotion of intercropping of soybean and maize grain yield and the Department of nitrogen and phosphorus accumulation increased.by 12.8% intercropping soybean grain, corn grain increased 35.6%; grain nitrogen accumulation increased by 12.1% for soybean and 20.2% for corn; phosphorus accumulation in soybean grain increased by42.9%, corn increased by 70.2% .6) The test under testing conditions, a single experiment under the conditions of summer corn and soybeans are obvious hydraulic lift, but at least within the experimental determination of the time, two kinds of crop growth stage hydraulic lift with the trend is not uniform; summer maize roots hydraulic lift, with the growth stage to promote increased significantly, peaked and then decreased; but the role of soybean root system for water changed slowly throughout the growing period. Overall, the test growing of crops during the intercropping Hydraulic Lift stronger than the single crop root hydraulic lift, with obvious coordination effect.