Guquan Experimantal Farm of Rural Ecological Engineering is an integrated farming system which is composed of a chicken farm, a pig farm, a fishing ground, an orchard, a mushroom hothouse,a duck farm, an earthworm plot and a marsh-gas fermenting system.The farm, 20 ha of area, started to design and build in the end 1984 and put it into operation in 1985.This paper has generally summarized the status of construction and production of the farm since its establishment. The farm’ s components and their scales, main design targets and parameters, and the ecolomic benefits the farm gained were described. In addition, the problems occured in the farm at present were also mentioned. 

This paper summarizes and analyzes all-sidedly the inputs and outputs of the matter, energy and capital from 1985 to 193Ton Guquan Experimental Farm of Ecological Engineering.The total output Value of the Experimental Farm over three years has reached 1 518 000 yuan RMB with a profit of 260 100 yuan RMB, It has provided markets with 490 000 kg of meats, including chickens, pork pigs, fish and so on. It will take only four years to recoup the farm’ s capital outlay. The analysis shows that the conversion rates of energy and nitrogen on the farm are 15.2% and 40% respectively, that the energy conversion rate can be increased by 2.7% and the use rate of nitrogen can be raised by at least 6% through using integratedly 81.8% of the internal trash or waste, and that the output value, profit and the conversion rates of energy and nitrogen have increased year by year. So, the authors suggest that the experiences of Guquan Experimental Farm should be popularized in the suburbs of cities and the countrysides with local conditions.

A prelimipary study Was made on the chemical composition of throughfall and its contribution to the nutrient recycling in rice field ecosystem at the late growth stages ( from booting to ripening stage )of hy-brid rice ( Xianyou no. 6 ) . The results showed that the chemical composition of precipitation remarkably changed when it passed through the rice canopy, the concentrationsm of N, P, K, Ca, Mg and Si Were increased.Peak concentrations of these elements occured in milky stage of rice growth.The amount of N, P, K, Ca, Mg and Si recycled by throughfall were 15.91, 1.11, 3-70, 1.13, 1.70 and 8.25 kg/ha respectively.It appeared that the nutrients (especially N)returned to soil by throughfall may be an important mechanism of nutrient recycling in rice field ecosystems. 

The preservation and discharge of soil nitrogen pool and its growth and decline trend in the ecological systems of loess plateau were discussed with the following resulfs:1. The nitrogen preserved in the top soil ( 0-20cm ) was 1.5×108 tons, and 5.0×10⁸ tons in the layer reached by the plant roots ( 0-1m). The nitrogen preserved in soils of high-yielding crop land was 2 - 3 t/ha; 1.5-2.0 t/ha in moderate yielding soils and 1.0-1.5 t/ha in low yielding soils.2. The total input to soil nitrogen pools was 235×10⁴ tons, among which 57.0% came from chemical nitrogen fertilizer, 36.6% from organic manure. The total output ,of nitrogen was 250×10⁴ t, among which 69.6% due to harvest of crops, 12.8% due to erosion.3. Great effort should be made to increase nitrogen content by applying chemical fertilizers and organic materials because negative balance of soil nitrogen pool usually occured. Non-production oulput of soil nitrogen should be decreased in order to keep a dynamic equilibrium of soil nitrogen. 

The concept of grassland agricultural ecosystem was proposed by the famous Chinese grassland ecolo-gist, Prof. Ren Jizhou based on the concrete condition of China. In this paper, based on the results of the Grassland Agricultural ecosystem research project carried out on the Loess Plateau, a perfect production pattern of the eco-households in grassland agricultural system on the Loess Plateau was suggested and the economic-ecological-social benefits of this pattern analyzed. 

More than 1400 sampling plots of 151 sites distributed throughout 13 counties "were surveyed, 88 families, 301 genera and 555 species ( including 15 varieties ) were recorded and sampled.The vicious and main weed species in the Various crop fields and habitates -were determined by the frequencies and dominances of weeds.The results showed that the main features of the weed flora of Taihu agricultural area were as follows; abundant and widely spreaded in species; highly diversified in family and genera; remarkable geographical characteristics of middle and lower Yangtze River valley; dominant anual lifeform; large proportion of hydrophyte and hygrophyte; obvious companionate with crops; sensitive to the environmental factors both ecofo-gical and cultivational. 

Results of acute toxicity test of four pesticides for Daphnia carinata was reported in this paper. The results showed that 48 hours LC₅₀ values of Deltamethrin, Methylparathion, Lindane (γ-BHC ) and Carbo-furaa to that species were 0.000123; 0.013; 0.075; and 0.076 ppm respectively. The degree of toxicily may be arranged in the following order: Deltamethrin>Methylparathion>Lindane>Carbofuran. According to the application-coefficients of the toxicants derived from the LC₅₀ values of these chemicals and their dosages in farm the safety use of the four pesticides has been evaluated and discussed. 

The Green Revalution started from 1960s was considered’ as one of the most outstanding achievements in the world’s agricultural development. Using hybrid seeds for crop productions in the Third World was the basic strategy of tte Green Revalution. However, only one third of the crop fields in the Third World benefited, many developing countries were still facing food shortage. The paper briefly reviewed some agricultural situations of the Third World after the Green Revalution and some technical strategies for a new Green Revalution. It was indicated that combining some modern biological techniques, such as tissue culture and recombinant DNA, with some ecological agro-techniques will be (he basic strategies of developing a new Green Revalution in the Third World. Some examples were given in the paper.

Based on the four outstanding characteristics of agricultural ecosystem Clarge amount of input and output; large quantity of auxiliary energy flow; shortened food chains; extended detritoiis chains) and the relationship of materials and energy flow between agricultural enterprises, the author proposed that the combination of agricultural ehterprises was the foundation of effective and multiple utilization of materials and energy in agricultural ecosystems. But this did not mean that all agricultural ecosystems made up of several agricultural enterprises could achieve promising results. In order to achieve the best result and to set up new systems in which materials and energy can be best utilized withi high effects and low. costs, seven general principlss were discussed; 1. Principle of adoptation to the local environmental condiitions. 2. Principle of determining reasonable numbers of agricultural enterprises. 3. Principle of pushing forward the key enterprises. 4.Principle of maintaining a suitable auxiliary energy flow. 5. Principle of expanding population of producers. 6.Principle of rational space arrangements. 7.Principle pf strengthening pest control. 

Ecological environment and land resources are vital to human kinds. With the development of mine industry, however, environmental problems are a frequeat occurence in many of tte nation’s coal regions such as increased mine spoils, land occupation, land subsidence, and soil erosion, etc.. A better recognition of these peoblems has resulted in more frequent iadetification of mined land reclamation. In Ctina, reclamation of disturbed land is just beginning, and will be significantly developed owing to the lack of land1 resources. The first step is to investigate the situation of land occupation and ecological environmental destruction and the achievements of reclamation in mine area,then, a plan for reclamation and vegetative restoration of mined lands can be drawn up. The second step is to undertake researches for its techniques and methods suitable for mine area in China.

Two main problems of environmental hydrogeology in the west low plain of Jilin Province -were discussed in this paper. They were- a. the impact of epidemic diseases on human health, and bt the saliniz-atioa of soil which damaged the ecological environment of that region. On the other hand, the man-made influence ( irrational utilization of ground water resources ) was also a main interfering factor. Control measures for these problems have been discussed.

In this paper, it was suggested that rural ecological environment be appraised by ecological index. The concepts and the computative measures of time and regional ecological indices were put forward. In accordance with the main ecological problems in the countryside, the author suggested fifteen items for appraisal and their standard values and relative importance. The application of this method was illustrated by an example. 

Cixi county is located in the coastal area, east of Ningbo city, Zhejiang Province. The County hav a stretched belt of sea beach rich in natural resources. In recent years, a rapid development of aquatic cultivation along that belt occured. But up to now its agriculture and livestock husbandry have not received much attention. As a result of an on-site investigation, ten major categories of beach vegetation have been proposed and the proper exploitation and utilization of beach plants in accordance with the real conditions of Soil, fishery and livestock suggested.

The proposition of the compartment model method brings us bopes that with this method We can solve she problem of matter cycling in agroecosystem quantitatively. In this paper based on data collected in our experiments and surveys a compartment model Was built, and the behavior of agroarosystem in nutrient cycling was simulated and predicted using computer for Doudian village in Beijing suburb, With the model tested in different decisions. It Was proved mathematically that the system Was tending lottfards a steady state and was observable as Well as coutrolable. Sensitivity of the system to perturbation Was highest with N and decreasing with P and K respectively. Recycling indicis of NPK in the system Were computed as a scientific basis provided for Ihe system management. The method of building a compartment model Was discussed in the paper, which suggests an improved modification of syslem analysis, with its shortcomings and limitations indicated. 

Tradeseantia paludosa Was Cultivated experimentally in an insulation room during the Cold season. The essential conditions of that room Were : temperature should be kept above 15℃ on average ; temperature above 15t musl be maintained 16 hours per day and a supplementary illumination of 2000 lux should be made by artificial lightening for 6 hours per day. In addition, proper treatments of recovery time should be arranged according to the room temperature. The result could be obtained in Warm Weather as Well.