A brief discussion on several issues that should be paid attention to when developing rural water-saving irrigation projects_What are the water-saving irrigation technologies?

Water-saving irrigation is a product of science and technology. It is an important measure to liberate and develop agricultural productivity. It is a revolution in traditional agricultural irrigation methods. It is important for promoting my country’s agricultural irrigation from extensive to intensive, and from extension to The transformation from main to connotation has important practical significance and far-reaching historical significance. In order to make it develop healthily and continuously, it is necessary to think from a dialectical point of view.

1. Thoughts on issues related to the development of water-saving irrigation

The purpose of water-saving irrigation is to reduce the ineffective loss of water resources during the irrigation process. According to the water requirements of crops in different growth periods, Carry out scientific irrigation at the right time and in the right amount to increase crop yields, improve the quality of agricultural products, and increase production and income. In the past 30 years, our country has accumulated rich experience in the research, application and promotion of water-saving irrigation, achieved remarkable results, and produced huge economic, social and ecological benefits. The practice of water-saving irrigation has brought benefits to people. However, there are always two aspects of the unity of opposites in everything, and both positive and negative aspects are included within it. When people praise the achievements of water-saving irrigation, they rarely consider the possible negative effects of water-saving irrigation.

For example, after channel lining and pipeline water delivery are adopted in well-canal combined irrigation areas or well irrigation areas, although the amount of surface water supply or groundwater extraction is reduced, the recharge of soil water and groundwater is also reduced. In the calculation of groundwater resources, from the perspective of water resources, reducing the amount of surface water supply does not equal the amount of water saved. It can be seen that improving the utilization rate of agricultural water supply should include improving the primary utilization rate and reuse rate. In addition to the irrigation water supply being used for crop transpiration and field evaporation, the surface part of the irrigation return water can be used by downstream irrigation areas. The water that seeps into the ground can be pumped out by wells for reuse. Some of the soil water can also be absorbed by crops.

It is worth noting that the implementation of water-saving irrigation has reduced leakage losses in the water transportation process and field leakage losses, but also reduced the amount of groundwater return water, breaking the original interconnection of water bodies in the region. and the water resources distribution system formed through mutual transformation. This system originally produced periodic recharge of groundwater in the region and had a positive impact on the ecological environment and agricultural production environment.

In recent years, due to global warming, northern my country has experienced continuous droughts for many years. Many inland rivers have dried up. The Yellow River has been drying up in both time and length. Groundwater in most areas of North China and Northwest China has been severely affected. It has been seriously over-exploited, and this situation has resulted in the availability of five natural water sources. If we want to continue to open source water, we must artificially conserve water sources. The amount of conservation is not only determined by objective natural conditions, but also related to the throttling itself that may harm supplies.

In view of this, in the current implementation of water-saving irrigation, we must not only realize that water is not inexhaustible, but also should not forget that water is recycled and can be reused. To understand this, we should further reflect on this issue. Under the condition of limited water resources, although people try their best to adopt various water-saving measures and implement careful irrigation, if they do not pay attention to the conservation of water resources, especially the conservation of groundwater resources, In the face of continuous drought, how long can this kind of water-saving irrigation be maintained?

2. Several issues that should be paid attention to when developing water-saving irrigation projects

Currently, the development of water-saving irrigation is in full swing in various places. It is necessary to learn from the experiences and lessons learned in the process of promoting water-saving irrigation in the past. , the following issues should be addressed.

1. Full demonstration should be made in advance on which water-saving irrigation technology to choose.

There are many kinds of water-saving irrigation technologies available at present, but they all have a certain appropriate range. , it is necessary to conduct investigation and research according to local conditions, conduct full demonstration and compare multiple plans, especially consider the national conditions of my country's rural land contract extension for 30 years, and choose the most suitable water-saving irrigation technical measures for local development. For example, areas with strong economic strength and severe shortage of irrigation water sources should develop sprinkler irrigation or micro-irrigation; if economic strength is weak, simple field water-saving irrigation techniques can be considered, that is, leveling the land, dividing small borders, trickle irrigation and trench irrigation Furrow irrigation, water-spot planting, etc., or a water-saving irrigation system can be adopted; for example, sprinkler irrigation or micro-irrigation can be considered for irrigating cash crops, fruit trees, vegetables and other crops with high output value; for irrigating field crops, anti-seepage channels or low-pressure pipeline transmission should be used. Water; for contiguous planting and large-scale operation and management, sprinkler irrigation can be considered; avoid being subjective and blind, comparing with each other, not acting according to economic laws, blindly pursuing high and new technology without considering your own conditions, and causing adverse consequences.

2. Strictly grasp the standards of water-saving irrigation

Although there are many water-saving irrigation technologies currently suitable for use in our country, to what extent can it be considered water-saving and benefits? There was no unified standard in the past as to what level is considered efficient and what standards should be used to measure it. Therefore, the quality of water-saving irrigation projects built in the past varies greatly. There are many so-called water-saving projects that seek to reduce investment in a one-sided manner, and the projects are very crude.

For example, in some low-pressure pipeline water transmission and irrigation projects, the underground pipes are only 1 to 2 meters per acre, and some are not even 1 meter, and all are ground moving hoses; in some sprinkler irrigation projects, the spacing between sprinkler heads and branch pipes is It is too large, causing leakage and spraying; some drip irrigation projects control two acres of land per moving capillary tube, etc. Although the project investment is low, the water-saving effect is not obvious; some only take certain single measures in the water delivery part, while the fields It is flood irrigation and extensive planting. Although water loss is reduced, the yield increase benefit is very low. If the standards for water-saving irrigation cannot be reflected in a scientific and realistic way, it will not only bring difficulties to macro-decision-making, but also directly affect the input and output of water-saving irrigation and the consolidation of existing water-saving irrigation projects.

3. Water-saving irrigation engineering technology should be closely integrated with agricultural water-saving and yield-increasing technology

In the past, during the development of water-saving irrigation, only single engineering technology was often emphasized, and no attention was paid to integrating agricultural Technical measures to increase production are supported. Although water is saved, the output efficiency is not high. Current agricultural water-saving and yield-increasing technologies generally include: water-fertilizer coupling technology, farming technology that retains water and moisture, rational layout of crops suitable for rainy planting, cultivation technology that improves crop drought resistance, straw or mulching technology, and the use of chemical agents to inhibit crop transpiration. Drought resistance, water absorption, water retention technology and drought-tolerant variety breeding technology, etc. In the future, special emphasis should be placed on selecting according to specific circumstances to assemble and match water-saving irrigation engineering technology with agricultural production-increasing technology to give full play to the comprehensive water-saving and production-increasing benefits.

4. Carefully choose high-quality water-saving irrigation equipment

In the process of developing water-saving irrigation in our country, a very important lesson is that the water-saving irrigation equipment used is not up to standard. , resulting in many existing water-saving irrigation projects not being able to function normally or even being scrapped. Therefore, the selection of high-quality water-saving irrigation equipment must be regarded as a major event in the construction of water-saving irrigation projects.