Analysis of the data accumulated in the past few decades indicates that drainage from farm fields has been steadily affecting the water quality of Tarim River, making it more salinized. In making use of the drainage as resources, there are several advantages:1) there already exist a certain number of drainage networks which are not very difficult to extend and remold:2) deserts can be used as object for drainage utilization;3) the drainage is still barely suitable for irrigation of salt tolerant plants. Based on different regions, the drainage can be used to expand sand control belts of arbors, shrubs and grasses, to increase vegetation coverage of Halosols deserts by salt tolerant plants, or to set up protective belts of salt tolerant plants around artificial oases.

As a case study,systematic analyses were performed of the climate, land and water resources and soil erosion in Shilongtou Valley of Wuyi County, Zhejiang Province, a red soil region in South China. The results of the analyses revealed the advantages and disadvantages of those resources. On such a basis, basic principles were brought forth for integrated development of red soil valleys. Technical measures and benefits of integrated development in red soil valleys were also summarized.

In order to study the effects of nitrogenous chemical fertilizer applied into paddy field on surface and ground water, a large scaled apparatus with simulated soil layers and ground water was erected for the experiment. Results show that even if urea was blended with bio mineral complex fertilizers and applied at a moderate or low rate, pretty high contents of organic nitrogen and N H ₃- N were detected in the surface water and solutions of the plow layer and the other layers at different depth, considerably polluting the groundwater, which lacks adequate replenishment. Since N O₃^-  - N will not last long in paddy field, its pollution may be neglected.

During the period of 1997-1998, the Dalate Grassland Ecosystem Experimental Station of the Grassland Institute, Chinese Academy of Agricultural Sciences carried out a research project determining soil CO 2 emission and CH 4 uptake fluxes of natural grassland, erected milkvetch grassland, corn field and potato field(the latter three had been reclaimed from the former). Results show that natural grassland, erected milkvetch grassland and upland farm field were all sinks for atmospheric methane.The conversion of natural grassland to farmland increased CO 2 emission from the soil and decreased CH 4 uptake by the soil from the atmosphere. CO 2 emission from the natural grassland and cornfield was in positive linear relationship with soil temperature in 5 cm depth while the CH 4 uptake of the soil was in negative linear relationship with soil moisture.

Based on the data of the 1981 topographic map and the 1997 landsat TM images of the area, dynamic changes in the lacustrine resources of the Dazonghu Lake and the Wugonghe Lake were investigated by means of RS and GIS. It was found that the areas and the storage capacities for flood detention of the two lakes have dropped significantly due to inning along the lakes for aquatic breeding, thus bringing about adverse effect on flood retention and transportation in the area, which in turn directly affect sustainable development of the social economy of the region. Aimed at the problem of shrinkage in the lake areas, corresponding countermeasures were brought forth for conservation of the lacustrine resources and sustainable development of the economy and as scientific basis for reference in rationalizing the utilization of the lacustrine resources.

Development of an oil field often causes pollution to its surrounding areas, negatively affecting the ecological environment therein. The development of Songfangtun Oil Field is cited as an example for the study to illustrate its impact on the surrounding pastures and the regularity of pasture restoration. Results show that during the processes of drilling, oil extraction, storage, conveyance and various other operations, large quantities of pollutants were generated, seriously polluting the pasture and affecting the growth of forage grasses. It takes 4-5 years for the pasture to restore the dominance of Aneurolopidium chinensis in drilling sites of chernozem and aeolian sand soils.

Based on an analysis of the status quo and characteristics of the ecological environment of the Yellow River Delta, ecological problems in the Delta are elaborated and countermeasures for its protection are put forward.

The study on dynamics of Bamanling residual in apples revealed that in 1995 and 1996 the primal accumulation of Bamanling were 0.470 and 0.761 mg/kg and its half life degradation period were 2.5 and 3.5 days respectively, showing a similar dynamic trend. Two treatments with different application rates and application times were designed (twice application of recommended dosage 2 000∶1 and three times application of higher dosage 1 000∶1). 14 days after the applications, the residual of Bamanling in the apples were 0.098 mg/kg and 0.132 mg/kg, both being well below the 1 mg/kg limit specified by FAO/WHO and, therefore, safe to humans.

From both practical and theoretical points of view, discussions were performed on role of eco agriculture in the construction of ecological demonstration areas as well as on definition and connotation of, and technical strategies and development orientation for the eco agricultural industrialization.

By analyzing the status quo of eco environment pollution and hazards caused by the application of pesticides in China, it has been revealed that the lack of essential environmental supervision and management of pesticides is the main cause of serious pesticide environmental pollution. Consequently, it brooks no delay that specific policies and measures should be worked out for controlling pesticide environmental pollution in China.

Phytoremediation of heavy metal contaminated soils, by using plants to make soil contaminants nontoxic, offers a cost effective “green” method for soil remediation. There are now four subsets of this technology applicable to soil remediation: (1) phytoextraction, using hyperaccumulator plants or high biomass metal accumulating plants to remove toxic metals from soil; (2) phytovolatilization, using plants to stimulate volatilization of metals from soil or plant surface; (3) phytofiltration, using plants to absorb, precipitate and concentrate toxic metals from water; and (4) phytostabilization, using plants to transform soil metals from toxic forms to less toxic forms. The use of plants to clean soils contaminated by toxic metals shows great potentiality. Also discussed are some important advances, made in the past few years, in making use of microorganisms for remediation of heavy metal contaminated soils.

Land eco economic system is a compound system that combines land ecological system and land economic system. An internal relationship lies in between sustainable land use and eco economic balance. The latter is the premise of the realization of the former. The objective of sustainable land use is to achieve harmonization and integration of ecological, economic and social benefits in the course of land exploitation. Therefore, it is essential to follow the principle of eco economy in sustainable utilization of land resources.

From the socio-economic viewpoint,causes of environmental deterioration are analyzed,leading to the following conclusions:intuitonstically,the failure in market regulation and governmental intervention is the major cause of the deterioration.However,the basic reasons of the failure are:firstly,the ambiguous proprietorship of the natural resources;secondary,lack of uniform criteria for valuating natural resources;and tertiary,inadequate standards to assess socio-environmental costs of various projects of and policies for exploitation of the natural resources.In order to halt the trend of the deterioration,it is essential to uproot these problems.

The western part of Jilin Province is an important component of the eco environmentally fragile zone in North China, where salinization induced desertification is the major restraining factor to the economic development of the region. The status quo of the salinization induced desertification and its serious effects on the animal husbandry, ecological balance, economic development and urbanization process there have been analyzed. Ecological engineering countermeasures are proposed and suggestions on governmental regulation are brought forth.

In Geheyan Flatland alongside the Qingjiang River,Cunninghamia lanceolata-Choerospondias axillaris forest is a typical secondary forest,rather complex in composition and structure,and dominated with deciduous broad-leaf species of trees,showing the characteristics of the transitional vegetation section in between mid-subtropics and north-subtropics.The species diversity of  the forest in this area is richer than in other secondary forests in the same region,which reveals that the community was disturbed moderately before.Today,the forest has been fairly well reestablished,tending to a mixed forest of evergreen broad-leaf and deciduous broad-leaf trees in succession.

 In Geheyan Flatland alongside the Qingjiang River, Cunninghamia lanceolata Choerospondias axillaris forest is a typical secondary forest, rather complex in composition and structure, and dominated with deciduous broad leaf species of trees, showing the characteristics of the transitional vegetation section in between mid subtropics and north subtropics. The species diversity of the forest in this area is richer than in other secondary forests in the same region, which reveals that the community was disturbed moderately before. Today, the forest has been fairly well reestablished, tending to a mixed forest of evergreen broad leaf and deciduous broad leaf trees in succession.

Investigations on the status quo of soil salinization and alkalization in Huanghe River Irrigation Plot of Baiyin District of Gansu Province, and analysis of its causes were carried out. On such a basis, comprehensive amelioration measures such as water saving irrigation, wastewater treatment, biological salt removal, etc. were proposed.