Establish a research method for the safe application of liquid digestate and investigate the safety threshold criteria for the application on wheat crops in soils with different acidity,thus maximize the utilization.The components of liquid di-gestate were analyzed to target those that inhibit the growth of wheat through following pot and filed trails.Then the maxi-mum concentration of each risk factor was determined.1)Volatile fatty acids(VFAs)inhibit the growth of wheat more sig-nificantly in acidic soils,while the inhibition effect was stronger in alkaline soils by inorganic ions.2)The inhibition of VFAs on wheat shows more severely at the tillering stage than overwintering stage due to high temperatures promoting the hydrolysis of acidic ions into molecules.3)The growth of wheat was stronger inhibited by inorganic ion in alkaline soils due to the greater salt retention capacity.4)The inhibition will be avoided when the liquid digestate is applied according to the nutrient demand testing logic,due to the main species of inorganic ions are nitrogen,phosphorus and potassium.VFAs have restricted concentration when the liquid digestate acts as fertilizer.In detail,for the soil of pH 7.5,the restricted con-centration of VFAs during different growth period of rice is respectively 45 mmol·L-1、11 mmol L-1、23 mmol L-1、30 mmol·L-1、18 mmol·L-1 for post-sowing stage,tillering to seedling stage,late tillering stage,overwintering stage and greening stage.Besides,the threshold concentration of VFAs becomes lower along with the pH value of soil.
维普
万方数据