Changes in vineyard soil parameters after repeated application of organic-inorganic amendments based on spent mushroom substrate

Sustainable agricultural practices influence s-metolachlor, foramsulfuron and thiencarbazone-methyl degradation and their metabolites formation

The effect of sustainable agricultural practices, such as mulching or the application of straw residues as an organic amendment, on the degradation, dissipation and persistence in the soil of S-metolachlor (SMOC), foramsulfuron (FORAM) and thiencarbazone-methyl (TCM) is still unclear. The objective here was to conduct a laboratory experiment to evaluate the impact of milled wheat straw (WS) simulating its individual use as mulch or applied as an organic amendment to two agricultural soils: unamended and WS-amended soils on the degradation kinetics of the herbicides SMOC, FORAM and TCM, and on the formation of their major metabolites at two incubation temperatures (14 °C and 24 °C). The degradation rate of SMOC on WS was 6.9-16.7 times faster than that observed for FORAM and TCM at both temperatures. The half-life (DT50) values were 1.1-10.6 times lower for FORAM than for SMOC and TCM in the unamended and WS-amended soils at 14 °C and 24 °C. The application of WS to soils increased the DT50 values from 1.1 to 11.2 times for all the herbicides at both incubation temperatures due to their higher adsorption and lower bioavailability. The herbicides recorded a faster degradation at 24 °C (1.2-3.9 times) than at 14 °C, according to Q10 values >1. SMOC metabolites were more persistent in WS-amended soils than in unamended ones, in agreement with the DT50 values recorded for the parent compound. The results indicate that the effect of the mulch applied to soils as an organic amendment was different depending on the herbicide and incubation temperature. The outcomes of this research can give key suggestions for reducing the effects of residual herbicides following sustainable agricultural practices by avoiding soil and groundwater contamination, which is one of the challenges involved in the application of chemical inputs.

Reed-mushroom-fertilizer ecological agriculture in wetlands: Harvesting reed to cultivate mushroom and returning waste substrates to restore saline-alkaline marshes

Construction of wetland ecological agriculture is recommended to perform ecological function and produce considerable economic value. A mode of wetland ecological agriculture was established on inland saline-alkaline marshes in Northeast of China here. This study used reed as substrate to cultivate Pleurotus citrinopileatus and return the waste substrate (SMS) to ameliorate the saline-alkalized soil. The biological efficiency of mushroom was 69.01 %, and the contents of sugar, crude protein, crude fat, and amino acids were 30.82 %, 23.07 %, 1.58 %, and 19.48 %, respectively in P. citrinopileatus. The cultivated mushrooms had higher contents of Ca, Fe, Zn and Cu, with lower levels of harmful heavy metals. When compared with initial substrates, the SMS remained 93.42 % fiber, 87.08 % carbon, 97.72 % nitrogen, 51.35 % phosphorus, and more Ca contents. Compared with the control, SMS application decreased the soil pH and electro-conductivity by 12.33 % and 30.75 %, and increased total nitrogen and organic matter by 34.98 % and 46.55 %, respectively. In addition to the soil improvements, the above- and belowground biomasses of reed were increased by 172.92 % and 59.64 %, respectively. The study indicated that reed could be used as mushrooms substrates, subsequently applied SMS to ameliorate the saline-alkaline soil. Our wetland ecological agriculture mode of "reed-mushroom-fertilizer" is available and effective for saline-alkaline wetland functioning and economic development.