First, rice greenhouses have large space, large capacity, artificially controlled temperature, and small influence of external air temperature on the indoor environment, which will help the seedlings to control temperature, humidity, and nutrients at different stages of growth and development. The seedling emergence rate and utilization rate of seedlings are higher. Second, small and medium-sized sheds around the small seedlings, seedlings in the middle, seedlings are not uniform, is not conducive to transplanting seedlings seedlings rate and utilization rate is low. Third, small and medium sheds are greatly affected by external temperature, high daytime temperatures, low nighttime temperatures, large temperature difference between day and night, rice seedlings susceptible to disease, seedling emergence slow, seedlings of poor quality, rice blight easily occur. According to the survey, seedlings planted on the same day have reached the standard for strong breeding after 35 days. However, the difference in leaf age between small and medium sheds is 0.5-1.0 leaves, and the number of white roots differs by 3-4. Fourth, rice nursery greenhouses can also be used in a shed. Spring rice seedlings are planted after the fall. In the autumn, the production of delayed vegetables will have a net income of 16.7 yuan per square meter; if the entire city is used for 70,000 hectares of paddy fields, the per hectare will be calculated at 100 square meters. Only one hectare of net income per hectare will be 1,670 yuan. The city can increase its net income by 116.9 million yuan. COVID-19 Infectious Disease Test Kit Corona viruses are enveloped RNA viruses that are distributed broadly among humans,other COVID-19 infectious diseases test Kit NINGBO AUTRENDS INTERNATIONAL TRADE CO., LTD , https://www.metests.com
mammals,and birds and that cause respiratory,enteric,hepatic and neurologic diseases.