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Soil soluble organic nitrogen (SON) plays an important role in nitrogen cycling. However, the dynamic and influencing factors of SON in paddy soil are largely unknown. In this study, 36-year fertilization experiments with different fertilized (control (CK), chemical fertilizer (NPK), chemical fertilizer combined with cow manure (NPKM) and chemical fertilizer combined with straw (NPKS)) paddy soils were selected to investigate the dynamic changes and influencing factors of the SON content during the whole rice growth stage. We found that NPK, NPKM and NPKS increased the soil SON content by 20.61 %, 51.33 % and 52.50 %, respectively, compared with CK. Compared with the NPK treatment, the average SON contents in the NPKM and NPKS treatments were significantly increased by 25.46 % and 26.44 %, respectively, but there was no significant difference between the NPKM and NPKS treatments. Soil SON contents in different growth stages under the same fertilization treatments showed maturity stage > tillering stage > flowering stage > jointing stage > seedling stage. Structural equation model (SEM) analysis showed that bacterial biomass was an important factor affecting soil SON content, with a total path coefficient of 0.92, including direct path coefficients of 0.24 for soil SON and indirect path coefficients of 0.68 for soluble organic carbon, microbial biomass nitrogen and protease activity. Redundancy sequencing analysis showed that SON contents during different rice growth stages were significantly affected by the bacterial community, i.e., Chloroflexi in the early growth stage and Proteobacteria and Bacteroidetes in the later stage contributed 5.33 %, 37.40 %, and 2.17 % to the SON content variation, respectively. Conclusively, the dynamics of SON in paddy soil under long-term fertilization treatments are closely related to both fertilization treatments and the rice growth stage and are mainly affected by the bacterial community.
Jing Yang; Wenqi Guo; Fei Wang; Fan Wang; Liming Zhang; Biqing Zhou; Shihe Xing; Wenhao Yang. Dynamics and influencing factors of soluble organic nitrogen in paddy soil under different long-term fertilization treatments. Soil and Tillage Research 2021, 212, 105077 .
AMA StyleJing Yang, Wenqi Guo, Fei Wang, Fan Wang, Liming Zhang, Biqing Zhou, Shihe Xing, Wenhao Yang. Dynamics and influencing factors of soluble organic nitrogen in paddy soil under different long-term fertilization treatments. Soil and Tillage Research. 2021; 212 ():105077.
Chicago/Turabian StyleJing Yang; Wenqi Guo; Fei Wang; Fan Wang; Liming Zhang; Biqing Zhou; Shihe Xing; Wenhao Yang. 2021. "Dynamics and influencing factors of soluble organic nitrogen in paddy soil under different long-term fertilization treatments." Soil and Tillage Research 212, no. : 105077.
Biochar combined with chemical fertilizer have been proven to be effective in improving soil fertility and crop yield. However, the effects of biochar-based fertilizer on yield, quality of tea and microbial community composition in tea orchard soil are unclear. To address this, four different treatments including CK (no fertilizer), B (biochar), F (chemical fertilizer), BF (biochar-based fertilizer) were performed in a tea orchard to explore the effects of different fertilizations on tea growth and the soil bacterial and fungal community. After one growing season, the BF increased the yield, 100-sproutweight and sprout density of tea by 39.2%, 26.6% and 10.7%, respectively, compared to CK. Amino acid content of F and BF, caffeine content of B, F and BF and the water extracts in BF were increased than those of CK. Soil bacterial and fungal diversity indices (chao1 and observed species) were generally higher under B than BF and F treatment. Cluster analysis revealed that bacterial and fungal community structures under BF treatment differed from those under CK, B and F treatment. The relative abundance of 10 key bacterial genera and 13 fungal genera were increased under BF treatment, including some plant beneficial microbes such as bacterial genera Rhodanobacter, Mizugakiibacter, Pedobacter, Sphingomonas and Devosia as well as fungal genera Rhodosporidiobolus, Chloridium, Amylocorticium, Clavulina, Inocybe and Mycofalcella. These genera were significantly positive correlated to yield and quality of tea. Redundancy analysis revealed that pH, total nitrogen and available potassium were the major properties shaping soil bacterial community, and dissolved organic carbon, exchangeable Ca, pH and total nitrogen were for fungal community. These results indicated that biochar-based fertilizer altered soil microbial community and enhanced some plant growth-promoting microbes, which were associated with the improvements of yield and quality of tea plants. Thus, the combination of biochar and chemical fertilizer is feasible for the improvements of tea growth and low nutrients acidic tea orchard soil.
Wenhao Yang; Changjuan Li; Shanshan Wang; Biqing Zhou; Yanling Mao; Christopher Rensing; Shihe Xing. Influence of biochar and biochar-based fertilizer on yield, quality of tea and microbial community in an acid tea orchard soil. Applied Soil Ecology 2021, 166, 104005 .
AMA StyleWenhao Yang, Changjuan Li, Shanshan Wang, Biqing Zhou, Yanling Mao, Christopher Rensing, Shihe Xing. Influence of biochar and biochar-based fertilizer on yield, quality of tea and microbial community in an acid tea orchard soil. Applied Soil Ecology. 2021; 166 ():104005.
Chicago/Turabian StyleWenhao Yang; Changjuan Li; Shanshan Wang; Biqing Zhou; Yanling Mao; Christopher Rensing; Shihe Xing. 2021. "Influence of biochar and biochar-based fertilizer on yield, quality of tea and microbial community in an acid tea orchard soil." Applied Soil Ecology 166, no. : 104005.
Soil soluble organic nitrogen (SON) is one of the most active components in soil nitrogen pools; however, limited information is available with regard to its driving factors, as well as their pathways and degrees of influence. In this study, structural equation modeling was used to analyze the driving factors, their significance, and pathways that affected SON dynamics in a waterlogged experiment of two typical paddy soils incubated for 80 d after green manure application. Soil pH, Eh, microbial biomass, enzyme activity, and SON dynamics were used to construct the structural equation model. Results showed that soil microbial biomass carbon (MBC), protease, glutamine, and initial organic matter (OM) directly and significantly affected soil SON with path coefficients corresponding to 0.405, 0.547, 0.523, and–0.623 (P < 0.01), respectively. Soil microbial biomass carbon and initial OM affected the SON dynamics indirectly through protease and glutamine activity. In addition, pH indirectly affected SON dynamics by glutamine activity. It is implied that soil MBC, protease, glutamine, and initial OM are the key factors affecting SON dynamics in the waterlogged paddy soils after green manure application. Our research indicated that structural equation modeling could provide an effective method to clearly recognize the impact, significance, and pathways of multiple factors on SON dynamics in paddy soils.
Jing Yang; Wenhao Yang; Fan Wang; Liming Zhang; Biqing Zhou; Rubab Sarfraz; Shihe Xing. Driving factors of soluble organic nitrogen dynamics in paddy soils: Structure equation modeling analysis. Pedosphere 2020, 30, 801 -809.
AMA StyleJing Yang, Wenhao Yang, Fan Wang, Liming Zhang, Biqing Zhou, Rubab Sarfraz, Shihe Xing. Driving factors of soluble organic nitrogen dynamics in paddy soils: Structure equation modeling analysis. Pedosphere. 2020; 30 (6):801-809.
Chicago/Turabian StyleJing Yang; Wenhao Yang; Fan Wang; Liming Zhang; Biqing Zhou; Rubab Sarfraz; Shihe Xing. 2020. "Driving factors of soluble organic nitrogen dynamics in paddy soils: Structure equation modeling analysis." Pedosphere 30, no. 6: 801-809.
Despite the increasing interest for biochar as a soil amendment, a knowledge gap remains on different particle size of biochar on soil phosphorous (P) availability and its impacts on microbial community. We hypothesized that biochar particle size and incubation temperature can significantly influence soil P availability and microbial community in subtropical acidic soil. A laboratory incubation study was established to investigate the effects of soil pH, available P and soil microbial responses to biochar addition having varying particle sizes using paddy soil and red soil under different incubation temperatures (15 °C & 25 °C). Biochar produced via pyrolysis of spent mushroom substrate feedstock was sieved into three particle sizes ((≤0.5 mm (fine), 0.5–1.0 mm (medium) and 1.0–2.0 mm (large)). The results exhibited that the fine particle biochar resulted in significantly higher release of P, soil pH, available P and bacterial species richness while simultaneously reducing the activities of phosphatase enzyme in both soils. Apprehending the impact of biochar particle size and incubation temperature, principal coordinate analysis (PCoA) predicted that soil microbial communities with fine particle biochar and high incubation temperature (25 °C) clustered separately. Redundancy analysis depicted that fine particle biochar had a direct association with available P and soil pH while high incubation temperature depicted a strong affinity for microbial communities. Hence, it is suggested that fine particle biochar and high incubation temperature may provide better habitat for microorganisms compared to the other particle sizes which may be due to improved soil pH and available P. However, a long term study of different biochar particles application in subtropical acidic soil needs to be pursued further for a more comprehensive understanding on this issue.
Rubab Sarfraz; Wenhao Yang; Shanshan Wang; Biqing Zhou; Shihe Xing. Short term effects of biochar with different particle sizes on phosphorous availability and microbial communities. Chemosphere 2020, 256, 126862 .
AMA StyleRubab Sarfraz, Wenhao Yang, Shanshan Wang, Biqing Zhou, Shihe Xing. Short term effects of biochar with different particle sizes on phosphorous availability and microbial communities. Chemosphere. 2020; 256 ():126862.
Chicago/Turabian StyleRubab Sarfraz; Wenhao Yang; Shanshan Wang; Biqing Zhou; Shihe Xing. 2020. "Short term effects of biochar with different particle sizes on phosphorous availability and microbial communities." Chemosphere 256, no. : 126862.
Interpolation plays an important role in revealing the spatial variations of soil organic matter (SOM). However, selecting an optimal one from multiple interpolations is challenging, particularly in the complex topography which is characterized by slope-rich terrain. In this work, the study area is a large region of slope-rich and complex topography, encompassing 9 cities and including 3 landforms of plain-platform, valley-basin, and hill-mountain. Based on 188,247 sampling sites, 12 widely used deterministic and geo-statistical interpolations were performed for farmland SOM estimation. Moreover, ancillary variables such as terrain, climate and soil cover patterns were combined with the optimal models of the above interpolations to examine the effects of incorporation of environmental variables on interpolation accuracy. The results showed that interpolation accuracy varied from landform to landform. The prediction accuracy of geo-statistical interpolations was generally higher than that of deterministic methods, and ancillary variables were generally effective to improve the interpolation accuracy. Specifically, for the entire region, simple kriging (SK) was the most accurate of these 12 interpolations, with a root-mean-square prediction error (RMSE) of 6.75 g kg−1 and a correlation coefficient (r) of 0.79 between the predicted and measured values (p < 0.01). Furthermore, when SK was combined with terrain, climate and soil cover patterns for interpolation (SK_T, SK_C, and SK_S), they performed better than SK. In terms of various landforms, such as hill-mountain and valley-basin, SK was still the best performing model, with RMSEs of 6.91 g kg−1 and 7.03 g kg−1, respectively. Further comparisons showed that SK_T, SK_C, and SK_S performed better than SK in hill-mountain and valley-basin. In plain-platform, the use of inverse distance weighting (IDW) was more desirable, with RMSE of 5.96 g kg−1, and RMSEs of methods where IDW was combined with terrain, climate and soil cover patterns (IDW_T, IDW_C, and IDW_S) followed the order of IDW_S > IDW > IDW_T > IDW_C. Our findings could inform interpolation of many environmental variables, not tied to SOM, in similar areas characterized by various landforms of a complex topography.
Jun Long; Yaling Liu; Shihe Xing; Liming Zhang; Mingkai Qu; Longxia Qiu; Qian Huang; Biqing Zhou; Jinquan Shen. Optimal interpolation methods for farmland soil organic matter in various landforms of a complex topography. Ecological Indicators 2019, 110, 105926 .
AMA StyleJun Long, Yaling Liu, Shihe Xing, Liming Zhang, Mingkai Qu, Longxia Qiu, Qian Huang, Biqing Zhou, Jinquan Shen. Optimal interpolation methods for farmland soil organic matter in various landforms of a complex topography. Ecological Indicators. 2019; 110 ():105926.
Chicago/Turabian StyleJun Long; Yaling Liu; Shihe Xing; Liming Zhang; Mingkai Qu; Longxia Qiu; Qian Huang; Biqing Zhou; Jinquan Shen. 2019. "Optimal interpolation methods for farmland soil organic matter in various landforms of a complex topography." Ecological Indicators 110, no. : 105926.
The prime objective of biochar production is to contribute to nutrients recycling, reducing waste and converting useful bio-wastes into carbon rich products in the environment. The present study was intended to systematically evaluate the effect of pyrolysis conditions and characteristics of feedstock influencing the generation of biochar. The study revealed the nutritional importance of waste mushroom substrate (WMS) biochar which may elevate soil nutritional status and soil quality. The results showed that the yields and properties of WMS biochar depended principally on the applied temperature where pyrolysis at higher temperatures, that is, 600 °C and 700 °C produced biochar having high ash, P and K contents. Moreover, numerous useful macro and micro nutrients such as Ca, Mg, Fe and Zn were observed to positively correlate with the increase in temperature. The WMS biochar in our study is highly alkaline which can be used to rectify acidic soil pH. Overall our results suggest that WMS biochar being a rich source of nutrients can be the best remedy to maintain and further enhance the soil nutritional status. Thus by interpreting biochar feedstock characteristics and pyrolysis conditions, the regulation of tailored WMS biochar manufacturing and application in soil can be facilitated.
Rubab Sarfraz; Siwei Li; Wenhao Yang; Biqing Zhou; Shihe Xing. Assessment of Physicochemical and Nutritional Characteristics of Waste Mushroom Substrate Biochar under Various Pyrolysis Temperatures and Times. Sustainability 2019, 11, 277 .
AMA StyleRubab Sarfraz, Siwei Li, Wenhao Yang, Biqing Zhou, Shihe Xing. Assessment of Physicochemical and Nutritional Characteristics of Waste Mushroom Substrate Biochar under Various Pyrolysis Temperatures and Times. Sustainability. 2019; 11 (1):277.
Chicago/Turabian StyleRubab Sarfraz; Siwei Li; Wenhao Yang; Biqing Zhou; Shihe Xing. 2019. "Assessment of Physicochemical and Nutritional Characteristics of Waste Mushroom Substrate Biochar under Various Pyrolysis Temperatures and Times." Sustainability 11, no. 1: 277.
View angle effects present in crop canopy spectra are critical for the retrieval of the crop canopy leaf area index (LAI). In the past, the angular effects on spectral vegetation indices (VIs) for estimating LAI, especially in crops with different plant architectures, have not been carefully assessed. In this study, we assessed the effects of the view zenith angle (VZA) on relationships between the spectral VIs and LAI. We measured the multi-angular hyperspectral reflectance and LAI of two cultivars of winter wheat, erectophile (W411) and planophile (W9507), across different growing seasons. The reflectance of each angle was used to calculate a variety of VIs that have already been published in the literature as well as all possible band combinations of Normalized Difference Spectral Indices (NDSIs). The above indices, along with the raw reflectance of representative bands, were evaluated with measured LAI across the view zenith angle for each cultivar of winter wheat. Data analysis was also supported by the use of the PROSAIL (PROSPECT + SAIL) model to simulate a range of bidirectional reflectance. The study confirmed that the strength of linear relationships between different spectral VIs and LAI did express different angular responses depending on plant type. LAI–VI correlations were generally stronger in erectophile than in planophile wheat types, especially at the zenith angle where the background is expected to be more evident for erectophile type wheat. The band combinations and formulas of the indices also played a role in shaping the angular signatures of the LAI–VI correlations. Overall, off-nadir angles served better than nadir angle and narrow-band indices, especially NDSIs with combinations of a red-edge (700~720 nm) and a green band, were more useful for LAI estimation than broad-band indices for both types of winter wheat. But the optimal angles much differed between two plant types and among various VIs. High significance (R2 > 0.9) could be obtained by selecting appropriate VIs and view angles on both the backward and forward scattering direction. These results from the in-situ measurements were also corroborated by the simulation analysis using the PROSAIL model. For the measured datasets, the highest coefficient was obtained by NDSI(536,720) at −35° in the backward (R2 = 0.971) and NDSI(571,707) at 55° in the forward scattering direction (R2 = 0.984) for the planophile and erectophile varieties, respectively. This work highlights the influence of view geometry and plant architecture. The identification of crop plant type is highly recommended before using remote sensing VIs for the large-scale mapping of vegetation biophysical variables.
Hanyue Chen; Wenjiang Huang; Wang Li; Zheng Niu; Liming Zhang; Shihe Xing. Estimation of LAI in Winter Wheat from Multi-Angular Hyperspectral VNIR Data: Effects of View Angles and Plant Architecture. Remote Sensing 2018, 10, 1630 .
AMA StyleHanyue Chen, Wenjiang Huang, Wang Li, Zheng Niu, Liming Zhang, Shihe Xing. Estimation of LAI in Winter Wheat from Multi-Angular Hyperspectral VNIR Data: Effects of View Angles and Plant Architecture. Remote Sensing. 2018; 10 (10):1630.
Chicago/Turabian StyleHanyue Chen; Wenjiang Huang; Wang Li; Zheng Niu; Liming Zhang; Shihe Xing. 2018. "Estimation of LAI in Winter Wheat from Multi-Angular Hyperspectral VNIR Data: Effects of View Angles and Plant Architecture." Remote Sensing 10, no. 10: 1630.
The anaerobic oxidation of ammonium (anammox) process plays a critical role in the loss of nitrogen (N) in paddy soils, yet the response of anammox to different fertilization is not well documented. In this study, three different fertilized (control, CK; soil treated with inorganic fertilizers, NPK; soil treated with inorganic fertilizer and involving the incorporation of straw, NPKS) paddy soils were selected to investigate the activity, functional gene abundance, diversity, and composition of anammox bacterial community using isotope-tracing technique, quantitative PCR assays, and Illumina sequencing. The anammox rate in the NPKS treatment was 2.4 nmol N g−1 soil h−1, significantly higher than that in CK and NPK treatments (1.7 and 1.8 nmol N g−1 soil h−1, respectively). Potential anammox contributed 6.2–7.8% to total N loss with the remainder being due to denitrification. Significant differences in the number of hydrazine synthase β-subunit (hzsB) gene were observed in three treatments with the highest value being observed in the NPK treatment. The anammox rate of per functional gene in the NPKS treatment (11.4 fmol day−1) was higher than that in CK and NPK treatments (8.3 and 7.0 fmol day−1, respectively). Three genera of anammox bacteria were identified: Candidatus Brocadia, Candidatus Anammoxoglobus, and Candidatus Scalindua, with Candidatus Brocadia being the dominant. Anammox bacteria diversity was significantly lower in the NPK than in CK and NPKS treatments as shown by Shannon, Simpson, Chao 1, and ACE indices (p < 0.05). The results showed that activity, abundance, and composition of anammox bacterial community depended on the type of fertilization.
San’An Nie; Xiumei Lei; Lixia Zhao; Yi Wang; Fei Wang; Hu Li; Wenyan Yang; Shihe Xing. Response of activity, abundance, and composition of anammox bacterial community to different fertilization in a paddy soil. Biology and Fertility of Soils 2018, 54, 977 -984.
AMA StyleSan’An Nie, Xiumei Lei, Lixia Zhao, Yi Wang, Fei Wang, Hu Li, Wenyan Yang, Shihe Xing. Response of activity, abundance, and composition of anammox bacterial community to different fertilization in a paddy soil. Biology and Fertility of Soils. 2018; 54 (8):977-984.
Chicago/Turabian StyleSan’An Nie; Xiumei Lei; Lixia Zhao; Yi Wang; Fei Wang; Hu Li; Wenyan Yang; Shihe Xing. 2018. "Response of activity, abundance, and composition of anammox bacterial community to different fertilization in a paddy soil." Biology and Fertility of Soils 54, no. 8: 977-984.
Soil soluble organic nitrogen (SON) concentrations in terrestrial ecosystems were influenced differently and substantially by both biotic and abiotic factors. This study aimed to ascertain the mechanisms of the impact of the key factors on the SON concentrations of subtropical mountain ecosystems in southeastern China using an integrative approach, which combined a field plot survey, gray relational analysis and structure equation modeling. The results showed that the soil organic matter, clay content, protease activity and bacterial biomass were the key factors controlling the dynamics of the SON concentrations in subtropical mountain ecosystems. Protease activity, by catalyzing the degradation of complex organic nitrogen to SON, had the highest direct influence on the SON concentrations among all of the impact factors with direct impact effect of 0.44. Organic matter, which serves as a primary source of SON and can increase soil protease activity and bacterial biomass, contributed the most significantly to the SON concentrations in both direct and indirect pathways with total impact effects of 0.87. Clay, by adsorbing SON and affecting organic matter accumulation and protease activity, also had important direct or indirect influences on the SON concentrations with total impact effects of 0.48. The impact of the bacterial biomass on the SON concentrations was likely to be concealed by accompanying nitrogen-degrading enzyme activity with total impact effects of 0.22. Thus, the organic matter, clay content and protease activity exerted greater total impact effects on the SON concentrations compared with the bacterial biomass. Protease activity and organic matter had a greater positive direct impact on the SON concentrations compared with the bacterial biomass and clay content, while organic matter also had greater positive indirect impacts on the SON concentrations than did the clay content. This study's results could help to elucidate the differential mechanism of SON dynamics among various terrestrial ecosystems.
Shihe Xing; Biqing Zhou; Liming Zhang; Yanling Mao; Fan Wang; Chengrong Chen. Evaluating the mechanisms of the impacts of key factors on soil soluble organic nitrogen concentrations in subtropical mountain ecosystems. Science of The Total Environment 2018, 651, 2187 -2196.
AMA StyleShihe Xing, Biqing Zhou, Liming Zhang, Yanling Mao, Fan Wang, Chengrong Chen. Evaluating the mechanisms of the impacts of key factors on soil soluble organic nitrogen concentrations in subtropical mountain ecosystems. Science of The Total Environment. 2018; 651 ():2187-2196.
Chicago/Turabian StyleShihe Xing; Biqing Zhou; Liming Zhang; Yanling Mao; Fan Wang; Chengrong Chen. 2018. "Evaluating the mechanisms of the impacts of key factors on soil soluble organic nitrogen concentrations in subtropical mountain ecosystems." Science of The Total Environment 651, no. : 2187-2196.
Applying legumes as green manure has been reported to improve soil fertility and alter soil bacterial community structure. Few studies have been conducted to determine the effects of Chamaecrista rotundifolia and Arachis pintoi mulching on soil bacterial communities in orchards. In this study, we described the bacterial community in the 0–20 cm soil profile under long-term (approximate 20 years) C. rotundifolia and A. pintoi mulching of persimmon orchards in subtropical and tropical China. The experiment included three treatments: (1) terraced persimmon orchard with A. pintoi mulching (TPA), (2) terraced persimmon orchard with C. rotundifolia mulching (TPC), and (3) terraced persimmon orchard with no vegetation mulching (TPN, CK). Soil chemical properties were significantly altered by long-term A. pintoi and C. rotundifolia mulching. Concentrations of total phosphorus (TP), available nitrogen (AN), soluble organic carbon (SOC), total soluble carbon (TSC), and organic matter (OM) were significantly higher in TPA and TPC soils than in TPN soils; TN and NH4+-N were highest in TPA soils and NO3−-N was highest in TPC soils. Soluble organic nitrogen (SON) and total soluble nitrogen (TSN) concentrations were significantly lower in mulched soils than in TPN soil. Illumina-based sequencing showed that soil bacterial community composition and structure were significantly altered by C. rotundifolia and A. pintoi mulching (TPC and TPA), and the changes in the dominant soil bacterial communities were demonstrated as reductions in the Simpson and Shannon indices. Proteobacteria (relative abundance 37.55%–50.94%) and Acidobacteria (relative abundance 9.47%–12.02%) were enriched in TPA and TPC soils, while Firmicutes (relative abundance 15.74%–22.00%) were higher in TPN soil. Further taxonomic analyses of Proteobacteria revealed that the relative abundance of Gammaproteobacteria and Deltaproteobacteria in PTA and TPC were significantly higher than in TPN, while the Betaproteobacteria in TPA and TPC were significantly lower than in TPN. Genus Phenylobacterium and Escherichia were enriched in TPC, Rhodoplanes and Escherichia were enriched in TPA, while, Kaistobacter, Sphingomonas, Burkholderia, and Enterobacter were enriched in TPN. Family Koribacteraceae classified as Acidobacteria was significantly higher in TPA than in TPN and TPC, and the genus Candidatus Koribacer of Acidobacteria was significantly higher in TPA and TPC than in TPN. In-depth taxonomic analyses of Firmicutes showed the relative abundance of family Bacillaceae, and Streptococcaceae and genus Bacillus and Lactococcus were lower in TPA and TPC than in TPN, while those of family Leuconostocaceae and Lactobacillaceae and genus Pediococcus were higher in TPA and TPC than in TPN. The genus Weissella was only observed in TPC and TPA. Our results indicate that long-term C. rotundifolia and A. pintoi mulching significantly influences the soil chemical properties and bacterial communities of persimmon orchards in subtropical and tropical China.
Zhenmei Zhong; Xiusheng Huang; Deqing Feng; Shihe Xing; Boqi Weng. Long-term effects of legume mulching on soil chemical properties and bacterial community composition and structure. Agriculture, Ecosystems & Environment 2018, 268, 24 -33.
AMA StyleZhenmei Zhong, Xiusheng Huang, Deqing Feng, Shihe Xing, Boqi Weng. Long-term effects of legume mulching on soil chemical properties and bacterial community composition and structure. Agriculture, Ecosystems & Environment. 2018; 268 ():24-33.
Chicago/Turabian StyleZhenmei Zhong; Xiusheng Huang; Deqing Feng; Shihe Xing; Boqi Weng. 2018. "Long-term effects of legume mulching on soil chemical properties and bacterial community composition and structure." Agriculture, Ecosystems & Environment 268, no. : 24-33.
Sampling density significantly affects the estimation of soil organic matter (SOM) concentration because it influences the interpolation accuracy. High sampling density may ensure adequate estimation, but it is costly. Low number of samples may underrepresent spatial variation and generate unacceptable predictions. Identifying a reasonable sampling density is challenging, especially where the topography is complex and characterized by slope-rich terrain. Here we addressed this challenge by taking a large region of complex topography as study area. The region had a total area of 1.24 × 105 km2 and can be separated into three typical landforms, namely, hill-mountain, valley-basin, and plain-platform. Out of 235,309 sampling sites, 188,247 were randomly selected as training sites, on which 20 sampling densities were designed and ordinary kriging was interpolated. The remaining 47,602 sites were used as testing sites to calculate the accuracies of SOM concentration predictions at different sampling densities in the entire region of complex topography and its various landforms. Overall, the prediction accuracy was positively correlated with the sampling density (R2 ≥ 0.98). Specifically, with increasing sampling density, accuracy improved slowly at first then rapidly. However, the tipping point at which prediction accuracy significantly improved with the increases of sampling density varied among the areas. These sampling densities were 0.10, 0.11, 0.10, and 0.09 samples per hectare for the entire region, valley-basin, hill-mountain, and plain-platform, respectively. Further comparisons showed that valley-basin was the landform that had the best performance in interpolation accuracy, followed by hill-mountain, entire region and plain-platform. Their normalized root mean square error (NRMSE) values were 23.86%–28.91%, 24.22%–29.54%, 25.32%–30.77%, and 31.21%–37.76%, respectively. Moreover, interpolation accuracy was more sensitive to sampling density in simple topography (flat regions such as plain-platform) than in complex landforms (slope-rich terrains like hill-mountain, and valley-basin). These variations in the relationships between interpolation accuracy and sample density suggest that topography must be considered when designing a scientific sampling density. More importantly, when a high level of interpolation accuracy and low sampling costs are required in regions of similar complex topography, our findings may help optimize soil sampling density.
Jun Long; Yaling Liu; Shihe Xing; Longxia Qiu; Qian Huang; Biqing Zhou; Jinquan Shen; Liming Zhang. Effects of sampling density on interpolation accuracy for farmland soil organic matter concentration in a large region of complex topography. Ecological Indicators 2018, 93, 562 -571.
AMA StyleJun Long, Yaling Liu, Shihe Xing, Longxia Qiu, Qian Huang, Biqing Zhou, Jinquan Shen, Liming Zhang. Effects of sampling density on interpolation accuracy for farmland soil organic matter concentration in a large region of complex topography. Ecological Indicators. 2018; 93 ():562-571.
Chicago/Turabian StyleJun Long; Yaling Liu; Shihe Xing; Longxia Qiu; Qian Huang; Biqing Zhou; Jinquan Shen; Liming Zhang. 2018. "Effects of sampling density on interpolation accuracy for farmland soil organic matter concentration in a large region of complex topography." Ecological Indicators 93, no. : 562-571.
Biochar application has been considered as a rich source of carbon which helps to improve the physico-chemical properties and fertility of the soil. In Pakistan, excessive use of nitrogen fertilizer is considered a serious problem, so it is of vital importance to examine the effect of biochar on soil with varying doses of nitrogen fertilizer. We hypothesized that addition of biochar to an alkaline calcareous soil could improve not only soil quality and crop yield but also nitrogen use efficiency (NUE), reducing the loss of nitrogen (N) in the form of denitrification, ammonia volatilization, and nitrate leaching. A pot experiment was conducted under 2-factorial completely randomized design having three replications to evaluate the NUE in biochar amended calcareous soil. Biochar was applied at the rate of 0%, 1% and 2% (w/w) in pots filled with 17 kg of soil using various levels of N (0%, 50% and 100% of recommended dose) on maize (Zea mays L.). Several soil quality indicators, uptake, and yield of maize were monitored. Biochar application significantly decreased soil pH, increased water-holding capacity, total organic carbon, maize yield, stomatal conductance, and nitrogen uptake in plant. The results of the study indicated that addition of biochar could not only decrease the use of inorganic fertilizers by improving its quality and yield as in our case biochar at the rate of 1% and N at the rate of 50% provided optimum output minimizing the economic cost eventually.
Rubab Sarfraz; Awais Shakoor; Muhammad Abdullah; Ammara Arooj; Azhar Hussain; Shihe Xing. Impact of integrated application of biochar and nitrogen fertilizers on maize growth and nitrogen recovery in alkaline calcareous soil. Soil Science and Plant Nutrition 2017, 63, 488 -498.
AMA StyleRubab Sarfraz, Awais Shakoor, Muhammad Abdullah, Ammara Arooj, Azhar Hussain, Shihe Xing. Impact of integrated application of biochar and nitrogen fertilizers on maize growth and nitrogen recovery in alkaline calcareous soil. Soil Science and Plant Nutrition. 2017; 63 (5):488-498.
Chicago/Turabian StyleRubab Sarfraz; Awais Shakoor; Muhammad Abdullah; Ammara Arooj; Azhar Hussain; Shihe Xing. 2017. "Impact of integrated application of biochar and nitrogen fertilizers on maize growth and nitrogen recovery in alkaline calcareous soil." Soil Science and Plant Nutrition 63, no. 5: 488-498.
The aim of this study was to investigate whether two subtropical fruit species, Dimocarpus longan Lour. (Wulonglin) and Eriobotrya japonica Lindl. (Zaozhong 6), could directly take up soluble organic nitrogen (N), and if there was differential uptake of different forms of N between the two species. The stable isotopic tracing experiment was carried out using three 15N-labeled tracers [glycine-2-13C-15N, (15NH4)2SO4, and K(15NO3)] to examine the short-term (2, 6, and 72 h) uptake and distribution pattern of N within the plant in 1-year-old seedlings of both fruit species. After glycine-2-13C-15N application, the ratios of 13C to 15N concentration in the roots and whole seedlings of both Wulonglin and Zaozhong 6 were close to 1:1 at 2 and 6 h, respectively, showing that both fruit species could directly take up intact glycine. The 15NH4+ absorbed by Wulonglin and Zaozhong 6 whole seedlings in the (15NH4)2SO4 treatment were 13.2 and 9.2 times higher than glycine-derived-15N, while 15NO3− absorbed in the K(15NO3) treatment were 27.7 and 7.7 times higher than glycine-derived-15N in the glycine-2-13C-15N treatment, respectively. This indicated that soluble organic N might not be the dominant N source taken up by both fruit species. Results also showed that Wulonglin preferred NO3−, while Zaozhong 6 preferred NH4+. The greater uptake of 15NH4+ and 15NO3− than glycine-derived-15N by both fruit species might be related to their long-term adaptation to the supply of large quantity of inorganic N via fertilization. To elucidate the mechanisms responsible for the differential uptake of different forms of N by these two fruit species, further studies on mycorrhizal associations, transporter genes, and glycine metabolisms are warranted. This study has demonstrated that both D. longan Lour. and E. japonica Lindl. seedlings were able to take up intact glycine directly, while the NO3− and NH4+ were still dominant N forms absorbed by both fruit species.
Biqing Zhou; Liming Zhang; Wenhao Yang; Yanlin Mao; Chengrong Chen; Shihe Xing. Differential uptake of soluble organic and inorganic nitrogen by two fruit species: Dimocarpus longan Lour. and Eriobotrya japonica Lindl. Journal of Soils and Sediments 2016, 17, 1579 -1587.
AMA StyleBiqing Zhou, Liming Zhang, Wenhao Yang, Yanlin Mao, Chengrong Chen, Shihe Xing. Differential uptake of soluble organic and inorganic nitrogen by two fruit species: Dimocarpus longan Lour. and Eriobotrya japonica Lindl. Journal of Soils and Sediments. 2016; 17 (6):1579-1587.
Chicago/Turabian StyleBiqing Zhou; Liming Zhang; Wenhao Yang; Yanlin Mao; Chengrong Chen; Shihe Xing. 2016. "Differential uptake of soluble organic and inorganic nitrogen by two fruit species: Dimocarpus longan Lour. and Eriobotrya japonica Lindl." Journal of Soils and Sediments 17, no. 6: 1579-1587.