How to deal with the decline in output of the solar greenhouse after a long time
The solar greenhouse is an energy-saving horticultural facility that can produce horticultural crops in cold areas without heating. It has the advantages of energy saving, environmental protection, and relatively low construction and operating costs. It has been widely promoted and applied in northern my country . In production practice, more and more farmers have discovered that although the daily agronomic management measures have not changed, the newly-built solar greenhouse is often three to five years after planting, the growth of the crops in the greenhouse gradually deteriorates, the pests and diseases gradually increase, and the yield is also greatly reduced. . There are two main reasons for this phenomenon: on the one hand, as the service life in the solar greenhouse increases, pathogenic bacteria and pest eggs in the greenhouse are gradually accumulating; on the other hand, because the solar greenhouse is a semi-enclosed environment Natural rainfall cannot enter the room, and the excess salt ions in the soil cannot be leached, resulting in the gradual deterioration of the physical and chemical properties of the indoor soil, and the accumulation of harmful organisms in the soil, leading to obstacles to continuous cropping of the soil.
The prevention and control of plant diseases and insect pests should be based on the principle of prevention. Common control measures include physical isolation, biological control, and ozone control. The solar greenhouse is a semi-enclosed facility. The front roof of the greenhouse is equipped with a top vent and a ground vent at the same location as the outside. In order to prevent external pests from entering the shed, a 30-50 mesh insect-proof net can be used for isolation; at the same time a buffer room Insect nets should also be added to the entrance connected to the greenhouse. For common pests such as whitefly, aphids, and thrips in the greenhouse, it can release natural enemies such as aphids, predatory mites, ladybirds and other natural enemies for biological control after crops are planted. Ozone not only has a spectrally efficient sterilization function, but also has a good control effect on pests such as Bemisia tabaci and Liriomyza huidobrensis.
The treatment measures for soil continuous cropping obstacles mainly include crop rotation, intercropping, high temperature and stuffy sheds, chemical fumigation, salt washing with water, additional soil, soilless cultivation, etc. Rotation and intercropping of crops of different families can slow down the occurrence of continuous cropping obstacles. For greenhouses with continuous cropping obstacles, high-temperature stuffy sheds and chemical fumigation can be used to kill soil pests and germs. The high-temperature stuffy shed is usually carried out during the stubble changing period when the summer is sunny and good. Before implementation, the greenhouse should be cleaned up, the shed should be filled with water, and all the vents should be closed for about one week, which can effectively kill the eggs and pathogens in the soil. The greenhouse can be closed before the stubble change in the cold autumn and winter seasons, and fumigation and disinfection with lime nitrogen and other agents can be used. When using the chemical fumigation method, attention should be paid to the greenhouse after the fumigation is fully ventilated and then cultivated. In areas where conditions permit, beneficial soil bacteria can be added. Washing salt with clean water reduces the conductivity of the soil by pouring a large amount of clean water into the greenhouse several times to dissolve the salt in the soil and then discharge it outdoors.
For greenhouses that cannot be relieved by the above methods, the soil method can be used to replace the soil of the cultivated layer in the greenhouse; for areas with conditions, the method of soilless cultivation can also be used.
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