Effects of inorganic and organic amendment on soil chemical properties, enzyme activities, microbial community and soil quality in yellow clayey soil

Abstract

Understanding the effects of external organic and inorganic components on soil fertility and quality is essential for improving low-yielding soils. We conducted a field study over two consecutive rice growing seasons to investigate the effect of applying chemical fertilizer (NPK), NPK plus green manure (NPKG), NPK plus pig manure (NPKM), and NPK plus straw (NPKS) on the soil nutrient status, enzyme activities involved in C, N, P, and S cycling, microbial community and rice yields of yellow clayey soil. Results showed that the fertilized treatments significantly improved rice yields over the first three experimental seasons. Compared with the NPK treatment, organic amendments produced more favorable effects on soil productivity. Notably, the NPKM treatment exhibited the highest levels of nutrient availability, microbial biomass carbon (MBC), activities of most enzymes and the microbial community. This resulted in the highest soil quality index (SQI) and rice yield, indicating better soil fertility and quality. Significant differences in enzyme activities and the microbial community were observed among the treatments, and redundancy analysis showed that MBC and available N were the key determinants affecting the soil enzyme activities and microbial community. The SQI score of the non-fertilized control (0.72) was comparable to that of the NPK (0.77), NPKG (0.81) and NPKS (0.79) treatments but significantly lower compared with NPKM (0.85). The significant correlation between rice yield and SQI suggests that SQI can be a useful to quantify soil quality changes caused by different agricultural management practices. The results indicate that application of NPK plus pig manure is the preferred option to enhance SOC accumulation, improve soil fertility and quality, and increase rice yield in yellow clayey soil.

Impact of management practices on soil microbial properties under wheat-cluster bean cropping system

“…Increased C mineralization in soils with organic manures is due to higher level of soil microbial activity attributable to build up of organic matter in organic manure amended soils as compared to unfertilized or inorganically fertilized soils (Dinesh et al, 2010;Liu et al, 2017). Sharma et al (2011) also reported a significant increase in carbon mineralization with the organic amendment.…”

Silicate Fertilizer Amendment Alters Fungal Communities and Accelerates Soil Organic Matter Decomposition

“…The plant was uprooted from the pot, shaken to remove excess soils on roots, and soils adhering to roots were washed with sterile distilled water and centrifuged at 10000 × g for 10 min to collect rhizosphere soils (Yergeau et al, 2014). The activities of hydrolytic enzymes [α-glucosidase (EC 3.2.1.20), β-1,4-glucosidase (EC 3.2.1.21), β-1,4-xylosidase (EC 3.2.1.37), and cellobiohydrolase (CBH; EC 3.2.1.91)] were measured by the microplate flurometric method, whereas oxidase enzyme [Phenol oxidase (EC 1.10.3.2) and peroxidase (EC 1.11.1.7)] activities were colorimetrically estimated using 96-well microplate according to the methods reported by Liu et al (2017).…”

Agronomic Management for Enhancing Plant Tolerance to Abiotic Stresses—Drought, Salinity, Hypoxia, and Lodging

“…Granular structure can be maintained or enhanced by amendments with organic matter like manure, slurry, compost, crop residues [24,25], or macromolecule polymers acting as soil conditioners [26,27]; or by mixing two or more soil layers in order to reach a more equilibrated texture [28]. Amendments improve soil physical properties, including increasing the content of water-stable aggregates, improving soil porosity and soil penetrability, improving water retention, decreasing soil bulk density and evaporation, and decreasing runoff amount and velocity.…”

“…Self-healing capacity of soils [20] Organic or inorganic soil mulching [22] Minimum tillage and no tillage [19,21] Tillage at moisture content at which the largest number of small aggregates is produced [23] Amendments: -organic matter (e.g., manure, slurry, crop residues) [24,25] -soil conditioners (polymers) [26,27] -mixing of two or more soil layers in order to reach a more equilibrated texture [28] Impact of rain and irrigation drops on bare soil surface [29] Runoff effect of rain and irrigation [29] Heavy traffic of agricultural machinery with high-volume pneumatics [28,32] Clods' exposure to freezing-thawing cycles [33] 4. The Impacts of Individual Stress Factors on Crops…”