Effects of Straw Incorporation on Soil Nutrients, Enzymes, and Aggregate Stability in Tobacco Fields of China

Abstract

Abstract:To determine the effects of straw incorporation on soil nutrients, enzyme activity, and aggregates in tobacco fields, we conducted experiments with different amounts of wheat and maize straw in Zhucheng area of southeast Shandong province for three years (2010)(2011)(2012). In the final year of experiment (2012), straw incorporation increased soil organic carbon (SOC) and related parameters, and improved soil enzyme activity proportionally with the amount of straw added, except for catalase when maize straw was used. And maize straw incorporation was more effective than wheat straw in the tobacco field. The percentage of aggregates >2 mm increased with straw incorporation when measured by either dry or wet sieving. The mean weight diameter (MWD) and geometric mean diameter (GMD) in straw incorporation treatments were higher than those in the no-straw control (CK). Maize straw increased soil aggregate stability more than wheat straw with the same incorporation amount. Alkaline phosphatase was significantly and negatively correlated with soil pH. Sucrase and urease were both significantly and positively correlated with soil alkali-hydrolysable N. Catalase was significantly but negatively correlated with soil extractable K (EK). The MWD and GMD by dry sieving had significantly positive correlations with SOC, total N, total K, and EK, but only significantly correlated with EK by wet sieving. Therefore, soil nutrients, metabolic enzyme activity, and aggregate stability might be increased by increasing the SOC content through the maize or wheat straw incorporation. Moreover, incorporation of maize straw at 7500 kg¨hm´2 was the best choice to enhance soil fertility in the tobacco area of Eastern China.

Effects of Different Land-Use Systems on Soil Aggregates: A Case Study of the Loess Plateau (Northern China)

“…A highly significant correlation (p < 0.01) between the aggregate fraction (>5 mm) and DSA WSA, MWD, and GMD was observed, in contrast to other size fractions and related soil properties (Table 6). The results of present study are aligned with the published papers [36,52,64,65]. Soil organic matter is the key compound affected by a range of microbial activities (living and dead organisms, decomposable SOM, and dead plant materials).…”

Soil Enzyme Activity as Affected by Tillage and Residue Management Practices under Diverse Cropping Systems

“…Evazi et al, (2003) reported that soil enzymatic activities (acid and alkaline phosphatases, alpha-glucosidase, arylsulfatase and urease) were higher in continuous corn under no tillage than conventionally tilled soil. Zhang et al, (2016) observed that activity of the enzymes (urease and sucrase) increased with the amount of straw applied. Incorporation of maize straw was more effective to increase enzyme activities as compared with wheat straw incorporation because of narrow C: N ratio of maize straw than wheat straw which facilitates faster decomposition of maize straw.…”

Aggregate Stability under Long-Term Fertilization Practices: The Case of Eroded Ultisols of South-Central China

“…Most often, improvements in aggregate stability were associated with an increase in soil organic carbon content [17][18][19]. Many studies have shown that organic amendments (e.g., manure and crop residues) to soil over time not only could maintain or increase soil fertility and SOC accumulation but also improve aggregation [6,14,[20][21][22][23]. Other workers, however, reported that SOC content and soil structure declined following the continuous application of mineral fertilizer alone [24].…”

“…In contrast, weaker correlations have been described between wateror acid-extractable C fractions and aggregate stability. Apart from SOC and its fractions, other soil characteristics such as sesquioxides, texture, and exchangeable cations are involved in soil aggregation and stabilization [19][20][21]35,36]. For instance, macro-aggregates in red soil tended to increase with the accumulation of SOC and Fe-oxides following the application of manure plus nitrogen fertilizer [37].…”