| Plug seedling is greatly accepted by farmers for saving labor and time, technology standardization, ease of long-distance transportation and mechanized transplanting. Seedlings have strong stress resistance and precocious efficiency. Plug seedling has become a new force with intensive high-efficiency agriculture. Application of substrate in vegetables, field crops and rice gave birth to the commercialization matrix. Peat is widely used in the world, but it is a non-renewable resources. For its limited available resources and slatternly distribution in China, peat is unable to meet the demand for our nursery industry. Therefore, the development of peat alternatives to meet the needs of modern nursery industry has important strategic significance. In this study, rice straw and sawdust as raw materials, substrate fermentation process and formulation in vegetables and rice were investigated. During this process, resistant microbial agents were added in order to develop disease-resistant and promotion nursery substrate. Meantime, the study of disease-resistant and promotion nursery substrate in the development, physiological characteristics and yield in vegetables and rice was conducted to lay the foundation for further resource use of industrial and agricultural waste resource. The main results are as follows:A comprehensive analysis of the physiological and chemical properties in rice and other agricultural waste resources was investigated, and rice seedling was tested, to further study the effect of BYM and PGPR and fragmentation of rice to fermentation and disease resistance in rice. The results showed that rice straw could be used as the main raw material, and rice husk and sawdust as accessories;coarse rice straw had the better decomposition degree, and addition of BYM could significantly improve the speed and quality of rice straw fermentation; addition of PGPR on rice seedlings had remarkable growth-promotion effect.The effects of addition of urea, chicken manure, rapeseed meal, rice husk and other accessories and explosive gas and fermentation aids to fermentation rate were investigated. The results showed that the substrate of sawdust+0.5% urea+10% chicken manure+20% rice husk had fastest fermentation rate. After construction of the heap, the maximum temperature reached 68℃ in 3rd day. The fermented compost was matured after 60d, and sawdust was brown sauce and fluffy material. The different aeration method had a significant effect on sawdust fermentation rate. The heap temperature rise the fastest in intermittent aeration (of aeration 15 minutes every 4 hours), and the maximum temperature reached 70 ℃ after 3 to 4 d, which could complete the fermentation after 7d. Addition of organic polymers (additive 1) and nitrifying bacteria (additive 2) could significantly affect the fermentation rate. The additive 1 could effectively reduce the EC and enhance fertilizer retention ability, and no adverse effects on rice seedlings emergence rate under a higher concentration of available nitrogen. Additive 2 could significantly reduce ammonia nitrogen and increase nitrate level, but not conductive to the synthesis of water-soluble humic acid.The effects of several biocontrol agents on watermelons, peppers, broccoli, and tomato blight were investigated in plug seedlings, and isolated and identified the disease, which is Phytophthora. The results of reverse test in field showed that seedlings with AR156-2 inoculation matrix displayed good disease resistance and growth-promoting effect. The disease control in peppers, watermelons and broccoli seedlings was 79.5%,87.5% and 83.1% respectively, the growth-promoting effects amounted to 35.3%,63,1% and 74.2% respectively, and the effect of disease-resistance substrate was better than metalaxyl and anchorage.The effects of different agents on the growth, yield and physiological characteristics in pepper were investigated, with 4 different microbial agents inoculated in pepper seedlings as materials. The results showed that substrates with addition of 4 microbial agents could promote the growth of pepper plants and improving the root vigor and yield, and AR had the best effect. Agents could optimize pepper root circumference microbial flora, significantly reducing the number of gungi and increasing the number of bacteria. Peppers with AR substrate had increase Ch1 a and total Ch1 contents, which significantly improved the net photosynthetic rate (Pn) and stomatal conductance (Gs) and reduced the intercellular CO2 concentration (Ci). Chlorophyll fluorescence analysis showed that photochemical quenching (qP) and actual photochemical efficiency ((?)PSII) were enhanced in the seedlings with the biological matrix. These results indicated that AR could be used as the inoculant of pepper seedling matrix, which not only to optimize rhizosphere microbial flora and improve photosynthetic performance, increasing production.In this study, the effects of matrix dosage, irrigation method, seeding rate, growth regulators on rice seedlings quality were investigated. The results showed that the thickness of 2.5-2.0 cm matrix has the best quality. Irrigation methods had greater impact to machine transplanted rice seedling quality, and the number of adventitious roots, root fresh weight and dry weight, root absorption area, root activity, roots twine force in matrix seedling were superior to water seedling and moist seedling. Different seeding rate on rice seedling quality also had greater impact, with the increasing of seeding rate, the leaves number of seedling was generally decreased, plant height increased, and the stem base width narrowed; the seedlings became weak, root number and length decreased. The results with the application of growth regulators to improve the quality of seedlings showed that spraying of uniconazole and paclobutrazol significantly inhibited the leaf length and plant height and increased leaf width and stem base width.The effect of substrate on drought resistance and growth and development were investigated. The results showed that moderate drought stress was conductive to improve the root to shoot ratio and plug seedlings could increase the proline content and SOD activity. In different ecological regions of rice, compared with the nutritive soil seedling, matrix seedling had fast seed emergence and seedlings growth was improved. Matrix seedling had 1-2 white roots, and seedlings began to grow in 1-2 days after transplanting, starting 2-3 tillers in 12 days. The nutritive soil seedlings began to growth in 3-7 days, and tiller retired latered 7days. The average yield of matrix seedling in rice could increase 5-8%, and in some areas yield even increased more than 10%. Analysis of production factors indicated that the reason of matrix improving yield is to raise panicle, seed setting rate and grains. |
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