One of frontiers in agricultural and environmental biotechnology for the arid regions: Micro-pressure drip irrigation technology theory and practices

With the goal of reducing cost and energy consumption of drip irrigation systems, the relationship between pressure and cost of drip irrigation systems, as well as the feasibility of reducing the operating pressure, were analyzed. The irrigation quality and reliability of micro-pressure drip irrigation systems were also studied. A theory of micro-pressure drip irrigation technology is proposed, and the components of this type of irrigation system are presented. The results indicate that micro-pressure drip irrigation technology is feasible and that it can significantly decrease initial drip irrigation system cost and recurring operating expenses. Micro-pressure drip irrigation can also overcome some of the clogging problems of conventional drip irrigation systems. It is suggested that micro-pressure dripirrigation will be a topic of importance in the future of agriculture and environmental biotechnology

Effects of different rhizosphere ventilation treatment on water and nutrients absorption of maize

The objective of this study was to explore the effects of different rhizosphere ventilation treatment on water and nutrients absorption of maize. The pot experiment was conducted using three methods: no ventilation, two day ventilation and four day ventilation, under conditions of the different levels of irrigation methods. As such, the influence of rhizosphere ventilation treatment on the physiological, water and nutrient absorption of maize was studied. Results showed that, with the increase inventilation frequency, plant height, leaf area and the content of chlorophyll in maize increased to a certain degree. Root activity of once in every four days ventilation was the biggest (8.237 mg/ (g·h)), followed by that of once in every two days ventilation (6.171 mg/ (g·h)), and that of no ventilation was the least (4.940 mg/ (g·h)). Consequently, it increased by 66.7 and 29.9%, respectively. The chlorophyll content experimental results showed that, rhizosphere ventilation treatment does not affect transpiration of potted maize and has no significant difference on the irrigation water utilization rate.Key words: Potted maize, rhizosphere ventilation, water, nutrients absorption, agricultural water-saving

Evaluation model development for sprinkler irrigation uniformity based on catch-can data

A new evaluation method with accompanying software was developed to precisely calculate uniformity from catch-can test data, assuming sprinkler distribution data to be a continuous variable. Two interpolation steps are required to compute unknown water application depths at grid distribution points from radial distribution of catch-cans' data: using both radial and peripheral interpolations. Interpolation by cubic splines was used to give more accurately interpolated values. This method has higher accuracy theoretically compared with conventional methods to analyze catch-can data. Water application depths were calculated at each grid point and uniformity coefficients were computed from the grid distribution maps of water application depths. This has value in assessing application uniformity of sprinkle irrigation designs

Constructing ecological-protecting barrier: Basic research of rainfall runoff regulation and application in the Loess Plateau of China and its implications for global arid areas

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