Microalgae-biochar compound biological fertilizer and preparation method thereof

Abstract

The invention discloses a preparation method of a micro algae-biochar composite bio-fertilizer. The method comprises the following steps: (1) separating representative photosynthetic microorganisms in soil crust, and preparing an exclusive culture medium; (2) screening and cultivating algae species having high nitrogen fixation ability and high carbon fixation ability by virtue of the exclusive culture medium in a photobioreactor; (3) enriching microalgae; (4) carrying out large-scale cultivation of microalgae; (5) collecting active microalgae; (6) collecting the biochar which is obtained by biomass pyrolysis, and carrying out drying treatment; and (7) compounding the active microalgae with the biochar, so as to prepare the micro algae-biochar composite bio-fertilizer. The invention also discloses a bio-fertilizer prepared by the method. The micro algae-biochar composite bio-fertilizer is prepared from the microalgae with high nitrogen fixation ability and pyrolysis biochar rich in high organic carbon as main matrixes; the advantages of the nitrogen-fixing microalgae and the biochar can be put into a full play; effective improvement and repair of the soil are achieved; and development of green low-carbon agriculture is promoted.

Description

technical field [0001] The invention relates to the biological field, in particular to a bio-based compound organic fertilizer and a production method thereof. Background technique [0002] Soil is the material basis for maintaining the biomass of the earth's surface ecosystem, and it is an inseparable natural resource and environment. At the same time, it also provides humans with various agricultural, forestry and pharmaceutical raw materials including food. However, with the continuous development of modern agriculture characterized by intensive utilization in our country, the threats to land resources, environment and human survival are becoming increasingly apparent. The main feature of intensive modern agriculture is to ensure and increase the yield of food crops through the high input of agrochemicals (mainly pesticides and fertilizers, etc.). The total amount of chemical fertilizers and pesticides used in my country ranks first in the world, and the amount used per ...

AI Technical Summary

Problems solved by technology

These methods can alleviate the problem of soil degradation to a certain extent, but there are still the following disadvantages: (a) physical remediation technology cannot fundamentally improve soil fertility, and the related equipment is expensive and the treatment cost is too high; (b) chemical remediation only It can change the properties of degraded soil in a short time, and the general chemical restoration technology needs water, so the restoration site needs to be close to the water source, and at the same time, the cost is increased due to the need to treat wastewater; (c) bioremediation can increase the content of organic matter and reduce the concentration of saline-alkali soil salinity and alkalinity, but the restoration period is long, monitoring and management are difficult, and the land after restoration can only be used as a green belt

Biochar itself is rich in organic carbon, but its mineral nutrient content is usually low, and its supplementary effect on soil nutrients is not as obvious as that of general fertilizers, and there are large differences in the mineral nutrient content of different biochar materials

Although biochar itself can be directly applied to the soil to improve soil fertility and increase crop yield, because the C / N of biochar is higher than that of other organic matter, its transformation in the soil requires a large amount of N, which seriously affects and restricts Soil N supply

When biochar is applied to the soil, it competes with crops for N, reducing N availability

Moreover, when biochar is directly applied to farmland, it will take a certain amount of time to achieve the effect. Driven by the reality of pursuing increased grain production and improving efficiency, it is still difficult to rely solely on biochar to increase soil fertility or improve soil.

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