Nutrient Recycling, Wheat Straw Decomposition, and the Potential Effect of Straw Shear Strength on Soil Mechanical Properties

Abstract

This study aimed to explore the release rate (RR) of wheat straw nutrients during straw return to a paddy field and examined the possible relationship between wheat stalk shear strength and the content of the remaining components in wheat straw. We used the nylon mesh bag technique to study the decomposition of straw nutrients such as total organic carbon (TOC), total nitrogen (TN), total phosphorus (TP), total potassium (TK), lignin, and cellulose over time. During the time span of 0–90 days, results showed a rapid decomposition rate with a diverse trend under different tillage operations. Furthermore, the decomposition rate was higher under the plough (PRP) conditions than under dry conditions (RP) or water rotation (PR). Moreover, under PRP conditions, the RR of TOC, TK, lignin, and cellulose increased, while the RR of TK was higher than 95% initially and then increased slightly. However, the carbon to nitrogen ratio was first increased and then decreased; similarly the RR of TP first increased and then decreased; a fluctuating pattern was observed for TN. Additionally, we found a strong correlation between wheat stalk shear strength and the remaining contents of lignin, hemicellulose, and cellulose, with R2 ≥ 0.91, which was higher than 0.82 after computing adjustments. Furthermore, the changing trend of nutrients and components and the relationship between shear strength and the content of the remaining components in wheat straw were used to evaluate the release characteristics of nutrients under straw return. The potential effects of the straw shear strength on soil mechanical properties were determined, providing a remarkable opportunity for acquiring nutrients for sustainable application of soil.

Study of C, N, P and K Release from Residues of Newly Proposed Cover Crops in a Spanish Olive Grove

“…This result implies that the release rate was, on average, always higher for P than for N. This was previously observed in pea under no-till farming [43]. Wang et al [29] indicated that P and K in straw are released during short-term straw return, while C and N are released during long-term straw return. In our case, only K was clearly released in the short term.…”

“…There is very scarce information on the nutrient release from aboveground residues during the decomposition of CCs in olive groves. Research on nutrient release has usually been performed in arable crops with no-till systems [28,29]. Some works have considered only the living stage of CCs [30].…”

Future climate conditions accelerate wheat straw decomposition alongside altered microbial community composition, assembly patterns, and interaction networks

“…While most studies have focused on litter decomposition in forests [5][6][7], less attention has been paid to this ecological process in agricultural lands. In agroecosystems, large quantities of straw are generated as byproducts from several crops, such as wheat and other cereals, and aid in maintaining soil organic matter content and supplying nutrients to subsequent crops [8].…”

Changes in some physical properties of the soils tread with wheat straw and rice husk under the rotation of white-head cabbage, tomato and wheat

“…Once the straw is returned to the soil, some nutrients are easily converted into CO2 by the mineralization of microorganisms in the soil. Wang et al (2020) have revealed that wheat straw components and nutrients are rapidly released in the natural environment under different tillage practiceswithout additives such as biomass and organic fertilizers-between 0 and 90 days. However, lignin remaining in the straw, cellulose and straw organic carbon in the hemicellulose remain in the soil longer because macromolecules such as lignin cannot be easily assimilated and converted by bacteria in the soil (Yang et al, 2019).…”