56 / 2023-05-27 18:41:59

Assessment of the fertility of loess soil affected by adding sheep Manure fertilizer in Northwest China

Natural organic fertilizer; Soil fertility; Correlation analysis; PCA

Natural organic fertilizer (NOF) has been used as a soil amendment to improve fertility and crop yield. However, the effects of NOF on fertility on loess soil have not been thoroughly investigated. To provide a scientific basis for establishing a reasonable fertilization model, this paper evaluated the effect of adding organic fertilizer on fertility in different soils. Three different loess soils (loessal soil, sierozem, dark loessal soil) were used as the research object, and sixteen indicators, such as pH values, soil organic carbon (SOM), ammonium nitrogen (AN), available phosphorus (AP), available potassium (AK), and exchangeable calcium (ECa) were measured using a JN-QYF type Soil Fertilizer Meter, which were evaluated to assess the effect of NOF addition on the fertility of different soil types. The soil fertility of the three groups (sheep manure, chemical fertilizer, and sheep manure combined with chemical fertilizer) was analyzed through a one-year field experiment. A field in Yongdeng County of Lanzhou city in China was selected as the experimental soil, and the planting crop was corn. The results showed that SOM, AN, AP, and AK were improved by adding NOF. Correlation analysis showed that SOM was significantly correlated with nitrate-nitrogen (NN), AK, and ECa. Principal component analysis (PCA) and cluster analysis (CA) were used to assess fertility in different types of loess soils. The PCA results showed that the first principal component (PC1) consisted of pH, AN, NN, and AK, and the second principal component (PC2) contained SOM, AP, ECa, Available copper (ACu), and Available chlorine (ACl). In the third principal component (PC3), however, Available silicon (ASi)and available boron (AB) accounted for only 19.8%. The cluster analysis (CA) used was comparable, and the results showed that the order of increasing soil fertility levels was loessal soil > sierozem > dark loessal soil. In conclusion, these results suggested that NOF used in combination with inorganic fertilizer could significantly improve soil fertility and regulate the soil nutrient balance in loess soils. Natural organic fertilizer can change the soil structure and promote the growth of soil crops. At the same time, it has important environmental significance to the balance of the ecological environment through the use of rural waste.