To minimize the nitrate stress derived from agricultural production on the environment, especially on the groundwater system, the total amount of nitrogen (chemical fertilizer nitrogen and organic waste manure nitrogen) applied per unit area should be restricted within the range of the nitrogen environmental assimilating capacity (NEAC) of the soil-plant system. We define NEAC as the yearly average rate of total nitrogen applied per year or in one cycle of cropping system, and NEAC satisfies not only productivity requirements but also environmental preservation requirements. We developed criteria to estimate NEAC, and using lysimeter test data, we estimated that the NEAC of a volcanic ash vegetable field in Japan was about 250-350 kg ha^-1. The environmental management standard for zinc (Zn) concentration in soil (120 mg kg^-1) seems to restrict the beneficial use of organic waste compost on cultivated land in Japan. Monitoring by using the method of evaluating the activity of soil micro-organisms may be useful to review the strict environmental management standard for Zn concentration in soil. Even when we applied sewage sludge and ZnSO₄ to some kinds of soil samples up to a level above 120 mg Zn kg^-1, the growth of soil micro-organisms was not inhibited in volcanic ash and alluvial soil samples. The environmental management standard for Zn concentration in soil should be determined for each kind of soil.