Dynamics of soil bacteria and fungi communities of dry land for 8 years with soil conservation management.

Microorganisms play an important role in nutrient cycling and ecosystem stability. This experiment studied the conservation management approaches [control without fertilizer (CK); fertilizer and different mulching based straw mulching (SM), plastic mulching (PM), ridge-furrow with plastic mulching (RFPFM), and green manure (GM)] effects on the soil microbial community structures in spring corn (Zea Mayis) dry land. The results showed that the bacterial phylum mainly included Proteobacteria (28.2%-36.8%), Acidobacteriota (9.1%-17.9%), Bacteroidota (5.6%-8.9%) and Actinobacteria (3.1-6.2%). The most richness fungal components were Ascomycota (35.2%-44.2%), Basidiomycota (3.3%-12%) and Mortierellomycota (3.4%-6.6%). Additionally, the highest Chao1 and abundance-based coverage estimator (ACE) indexes of bacteria (2931.9 and 2953.7) and fungi (1083.316 and 1100.650) were present in RFPFM that indicating the richest microbial abundance, the highest Shannon and Simpson indexes was exist in PM (9.332 and 0.996) for bacteria and RFPFM (6.753 and 0.974) for fungi. Therefore, this study reveals the conservation management of fertilizer addition and mulching management obviously promoted microbial diversity and altered the superior microbial distribution that provides a potential way for agricultural sustainable management approaches in production practice during circular economy.

A two-year field study of phytoremediation using Solanum nigrum L. in China.

A two-year in-situ phytoremediation trial was launched in Shenyang Zhangshi (Sewage) Irrigation Area (SZIA). The phytoremediation efficiency of Solanum nigrum L. was determined, by both monitoring the change of soil Cadmium level in the upper 20 cm of soil, and calculating the plant uptake of soil Cd. After two years experimental, by monitoring the soil Cd concentrations, The Cd concentrations decreased on average from 2.75 mg kg(-1)to 2.45 mg kg(-1) in the first year and from 2.33 mg kg(-1) to 1.53 mg kg(-1) in the second year, amounting to a decrease by a factor of 10.6% in the first year and 12% in the second year. After two years phytoremediation by S. nigrum, Cd concentrations of the seven experimental plots with S. nigrum growth decreased from 2.75 mg kg(-1) to 1.53 mg kg(-1), a decrease by a factor of 24.9%. And the soil Cd concentration decreased only 2.1% and 1.7% in the bared experimental plot. And the calculating of Cd uptake by S. nigrum shown that, the plants uptake 4.46% and 5.18% of the total soil Cd in 2008 and 2009, while the soil Cd concentrations decreased by a factor of 10.6% in 2008 and 12.1% in 2009.

Potential of Gibberellic Acid 3 (GA3) for Enhancing the Phytoremediation Efficiency of Solanum nigrum L.

A microcosm experiment with artificially contaminated soils was conducted in a greenhouse to evaluate the effect of gibberellic acid 3 (GA3) on phytoremediation efficiency of Solanum nigrum L. The GA3 was applied at three different concentrations (10, 100, 1000 mg L(-1)) to S. nigrum. Results indicated that GA3 can significantly (p < 0.05) increase the biomass of S. nigrum by 56 % at 1000 mg L(-1). Concurrently, GA3 application increased Cd concentrations in the shoot of S. nigrum by 16 %. The combined effects resulted in an increase in the amount of Cd extracted by a single plant by up to 124 %. Therefore, it is possible to use GA3 to promote the Cd phytoremediation efficiency of S. nigrum.