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Excessive, long-term chemical fertilizer application adversely affects soil quality and maize yield. The combined application of biochar with chemical fertilizer can increase maize yield and improve soil fertility. A four-year field experiment was conducted to determine soil physio-biochemical properties and maize yield under a soybean–maize rotation in the black soils of Northeast China. There were five treatments, including no fertilization (CK), fertilizer (NPK), fertilizer + biochar (15.75 t·hm−2, BC1), fertilizer + biochar (31.50 t·hm−2, BC2), and fertilizer + biochar (47.25 t·hm−2, BC3). Compared with CK, the number of macroaggregates and the average weight diameter of soil aggregates in BC2 treatment increased significantly by 10.3% and 24.5%, respectively. The soil pH in the study area was 7.03, and it increased in all treatments except for BC1. The highest pH of 7.17 was recorded in NPK and BC2 treatments, which was around the optimal soil pH. In contrast to the CK and NPK treatments, the biochar application increased soil organic carbon (SOC) and total nitrogen (TN) content. The BC2 treatment improved soil C/N and increased the copy number of soil bacteria by 25.6% compared to CK. The combined application of chemical fertilizer and biochar was better than NPK treatment alone, and improved soil mechanical composition and fine soil particle contents (powder and clay). Mixed biochar with chemical fertilizer application also significantly increased maize yield and the weight of 100 grains increased from 9.5% to 10.9% compared to CK. The maize yield of the three fertilizer and biochar treatments was higher than treatments with applied chemical fertilizer alone, in the order of BC2 > BC3 > BC1 > NPK > CK (BC2 treatment increased by 34.8%). Additionally, the maize yield was significantly and positively correlated with soil aggregates, organic carbon and total nitrogen (p < 0.05) as well as the 100-grain weight (p < 0.01). The application of 31.50 t·hm−2 (BC2 treatment) of biochar can enhance soil physicochemical properties and improve maize yield. [ABSTRACT FROM AUTHOR]

This paper investigated the effects of liquid-solid ratio, extraction time, extraction temperature and alkali concentration on the extraction rate of millet bran polysaccharides by the enzymatic hydrolysis and alkaline extraction method, then the L9 (34) orthogonal test was designed to optimize the extraction process according to the single factor experiment.The optimum parameters were obtained as follow: 15:1 liquid-solid ratio, five hours extraction time, 80° extraction temperature, and 0.7 mol/l concentration of sodium hydroxide. The extraction rate of millet bran polysaccharide reached 11.46% through the verification experiments under these conditions,and the RSD was 1.79%. Therefore, it can provide some experimental basis for the scientific research of millet bran polysaccharides in the future.

Paprika was soaked in n-hexane to extract paprika pigment by using ultrasonic and microwave assisted extraction (UMAE). The effects of different operating variables were investigated and the extraction condition was optimized through orthogonal design: ultrasonic power of 50 w, microwave power of 240 w, powder-solvent ratio of 1: 25 (g/mL), microwave time of 600 s, paprika particle size of 60 mesh. At these conditions, the color value of 147 of paprika pigment was reached. Compared with the conventional water bath extraction method, UMAE has the advantages of shorter extraction time and higher efficiency, which may be related to the effect of UMAE on destroying the cellular structure of paprika.