Soil organic and inorganic carbon sequestration by consecutive biochar application: Results from a decade field experiment     

Siwei Shi  Qingzhong Zhang  Yilai Lou  Zhangliu Du  Qian Wang  Ning Hu  Yidong Wang  Anna Gunina  Jiqing Song 《Soil Use and Management》2021,37(1):95-103

Biochar addition can expand soil organic carbon (SOC) stock and has potential ability in mitigating climate change. Also, some incubation experiments have shown that biochar can increase soil inorganic carbon (SIC) contents. However, there is no direct evidence for this from the field experiment. In order to make up the sparseness of available data resulting from the long‐term effect of biochar amendment on soil carbon fractions, here we detected the contents and stocks of the bulk SIC and SOC fractions based on a 10‐year field experiment of consecutive biochar application in Shandong Province, China. There are three biochar treatments as no‐biochar (control), and biochar application at 4.5 Mg ha^?1 year^?1 (B4.5) and 9.0 Mg ha^?1 year^?1 (B9.0), respectively. The results showed that biochar application significantly enhanced SIC content (3.2%–24.3%), >53 μm particulate organic carbon content (POC, 38.2%–166.2%) and total soil organic carbon content (15.8%–82.2%), compared with the no‐biochar control. However, <53 μm silt–clay‐associated organic carbon (SCOC) content was significantly decreased (14%–27%) under the B9.0 treatment. Our study provides the direct field evidence that SIC contributed to carbon sequestration after the biochar application, and indicates that the applied biochar was allocated mainly in POC fraction. Further, the decreased SCOC and increased microbial biomass carbon contents observed in field suggest that the biochar application might exert a positive priming effect on native soil organic carbon.  相似文献   

Responses of soil nematode community structure to soil carbon changes due to different tillage and cover crop management practices over a nine-year period in Kanto,Japan     

《Applied soil ecology》2015

The response of the soil food web structure to soil quality changes during long-term anthropogenic disturbance due to farming practices has not been well studied. We evaluated the effects of three tillage systems: moldboard plow/rotary harrow (MP), rotary cultivator (RC), and no-tillage (NT), three winter cover-crop types (fallow, FL; rye, RY; and hairy vetch, HV), and two nitrogen fertilization rates (0 and 100 kg N ha⁻¹ for upland rice, and 0 and 20 kg N ha⁻¹ for soybean production) on changes in nematode community structure. Sixty-nine taxa were counted, total nematode abundance (ALL), bacterial feeders (BAC), predators (PRD), omnivores (OMN), and obligatory root feeders (ORF) were more abundant in NT than in MP and RC, but fungal feeders and facultative root feeders (FFR) were more abundant in RC than in NT and MP. Cover crop also influenced nematode community structure; rye and hairy vetch were always higher in ALL, BAC, FFR, ORF, and OMN than fallow. Seasonal changes in nematode community structure were also significant; in particular, as soil carbon increased, nematode abundance also increased. The relationship between nematode indices and soil carbon was significant only in NT, but not in MP and RC. In NT, with increasing soil carbon, enrichment index and structure index (SI) were positive and significant and channel index was negative. Bulk density was significantly negatively correlated with FFR and ORF. Seasonal difference in nematode community between summer and autumn was larger in an upland rice rotation than in a soybean rotation. Over the nine-year experiment, SI increased not only in NT but also in MP and RC, suggesting that repeated similar tillage inversions in agroecosystems may develop nematode community structures adapted to specific soil environmental conditions. Because NT showed the highest values of both SI and soil carbon, the increase of soil carbon in NT is expected to have a great impact on developing a more diverse nematode community structure.  相似文献   

Sugar beet rotation effects on soil organic matter and calculated humus balance in Central Germany     

《European Journal of Agronomy》2016

In order to quantify the influence of land use systems on the level of soil organic matter (SOM) to develop recommendations, long-term field studies are essential. Based on a crop rotation experiment which commenced in 1970, this paper investigated the impact of crop rotations involving increased proportions of sugar beet on SOM content. To this end, soil samples were taken in 2010 and 2012 from the following crop rotation sequences: sugar beet–sugar beet–winter wheat–winter wheat (SB–SB–WW–WW = 50%), sugar beet–sugar beet–sugar beet–winter wheat (SB–SB–SB–WW = 75%), sugar beet–grain maize (SB–GM = 50%) and sugar beet-monoculture (SB = 100%); these were analysed in terms of total organic carbon (TOC) and microbial biomass carbon (MBC) content, MBC/TOC ratio and the TOC stocks per hectare. In addition, humus balances were created (using the software REPRO, reference period 12 years) in order to calculate how well the soil was supplied with organic matter. In the field experiment, harvest by-products (WW and GM straw as well as SB leaves) were removed. After 41 years, no statistically significant differences were measured between the crop rotations for the parameters TOC, MBC, MBC/TOC ratio and the TOC stock per hectare. However, the calculated humus balance was significantly affected by the crop rotation. The calculated humus balance became increasingly negative in the order SB–SB–WW–WW, SB–SB–SB–WW, SB monoculture and SB–GM, and correlated with the soil parameters. The calculated humus balances for the reference period did not reflect the actual demand for organic matter by the crop rotations, but instead overestimated it.  相似文献   

藏北高原退化高寒草甸土壤团聚体有机碳变化特征   总被引：1，自引：0，他引：1  

于宝政  彭岳林  蔡晓布 《草地学报》2017,(6):1212-1220

采用湿筛法对藏北高原退化高寒草甸表层(0~10cm)、亚表层(10~20cm)土壤团聚体有机碳及其变化进行了研究。结果表明,高原冷湿环境中退化草地表层、亚表层SAOC的下降幅度随草地退化加剧均趋于显著提高,轻度、严重退化草地表层各粒级SAOC降幅均明显高于亚表层;草地退化缩小了不同土层间SAOC含量的差异,草地退化程度越高则表层、亚表层间SAOC含量的差异越小,退化草地大团聚体(0.25mm)SOC、微团聚体(0.25mm)SOC含量的土层分布亦呈相同趋势。轻度退化草地不同土层大团聚体SOC降幅均较高,严重退化草地不同土层微团聚体SOC降幅则较高;正常草地、轻度退化草地、严重退化草地表层大团聚体SOC/微团聚体SOC比值分别为0.95,0.87,1.55,亚表层分别为0.96,0.72,2.33,表明轻度、严重退化草地中大团聚体SOC含量随土层加深分别更趋下降、更趋提高。退化草地表层、亚表层SAOC贡献率在总体上亦均按2~0.25 mm,2 mm,0.25~0.053mm,0.053mm的顺序依次大幅降低,表明不同土层大团聚体SOC贡献率均较高。土壤团聚体与SAOC、SOC与SAOC间的关系受草地退化程度的影响。  相似文献   

Estimation of phenotypic variability in symbiotic nitrogen fixation ability of common bean under drought stress using 15N natural abundance in grain     

《European Journal of Agronomy》2016

Common bean (Phaseolus vulgaris L.) is the most important food legume, cultivated by small farmers and is usually exposed to unfavorable conditions with minimum use of inputs. Drought and low soil fertility, especially phosphorus and nitrogen (N) deficiencies, are major limitations to bean yield in smallholder systems. Beans can derive part of their required N from the atmosphere through symbiotic nitrogen fixation (SNF). Drought stress severely limits SNF ability of plants. The main objectives of this study were to: (i) test and validate the use of ¹⁵N natural abundance in grain to quantify phenotypic differences in SNF ability for its implementation in breeding programs of common bean with bush growth habit aiming to improve SNF, and (ii) quantify phenotypic differences in SNF under drought to identify superior genotypes that could serve as parents. Field studies were conducted at CIAT-Palmira, Colombia using a set of 36 bean genotypes belonging to the Middle American gene pool for evaluation in two seasons with two levels of water supply (irrigated and drought stress). We used ¹⁵N natural abundance method to compare SNF ability estimated from shoot tissue sampled at mid-pod filling growth stage vs. grain tissue sampled at harvest. Our results showed positive and significant correlation between nitrogen derived from the atmosphere (%Ndfa) estimated using shoot tissue at mid-pod filling and %Ndfa estimated using grain tissue at harvest. Both methods showed phenotypic variability in SNF ability under both drought and irrigated conditions and a significant reduction in SNF ability was observed under drought stress. We suggest that the method of estimating Ndfa using grain tissue (Ndfa-G) could be applied in bean breeding programs to improve SNF ability. Using this method of Ndfa-G, we identified four bean lines (RCB 593, SEA 15, NCB 226 and BFS 29) that combine greater SNF ability with greater grain yield under drought stress and these could serve as potential parents to further improve SNF ability of common bean.  相似文献   

Soil CO2 emission in sugarcane management systems     

Rose Luiza Moraes Tavares  Zigomar Menezes de Souza  Diego Silva Siqueira  Newton La Scala Júnior  Alan Rodrigo Panosso 《Acta Agriculturae Scandinavica, Section B - Plant Soil Science》2013,63(8):755-762

Sugarcane management systems affect soil attributes such as the carbon cycle. This fact has stimulated the sugar and alcohol industry to refine the sugarcane production systems by replacing the pre-harvest burning (PB) and manual harvest with mechanized harvesting followed by residue deposition. The aim of this study was to evaluate different management systems with respect to C cycling carbon dioxide and soil parameters (chemical, physical and biological) which were determined over the season. Three sugarcane cultivation systems were evaluated at the following periods: (a) PB, (b) 5-year green harvest and (c) 10-year green harvest. The results indicated that CO₂ emission was 36% greater in the 10-year sugarcane green harvest system than in the PB system. The bulk density and macroporosity were the factors that were most affected by the different sugarcane management systems and that significantly influenced soil CO₂ emissions. The principal component analysis showed that soil CO₂ emission was 18% influenced by base saturation (V%) and 14% by pH, especially in the PB area. Additionally, 19% was affected by carbon and macroporosity in the 5- and 10-year green harvest areas, respectively. From our results, it can be concluded that the most CO₂ emissions are in the areas of sugarcane green, this is due to the higher carbon concentration when compared with the area of burning sugarcane. The parameters that most influenced the CO₂ emissions were bulk density, porosity, macroporosity, pH and V%.  相似文献   

An Overview of Research on Microbial Herbicide     

《农业科学与技术》2013,(10):1468-1470,1485

The development of microbial herbicide for weed control has been serious- ly regarded all over the world and has made rapid progress in recent years. This paper presents a comprehensive review on domestic and abroad research progress of microbial herbicide and mainly introduces the microbial herbicide products and mi- crobial sources with commercialization potential, and then proposes an outlook for their development tendency and application prospect.  相似文献   

An experimental study of charcoal degradation in a boreal forest     

《Soil biology & biochemistry》2013

Degradation rates of pyrogenic carbon (PyC) under natural environmental conditions are largely unknown. Here we present results from a field experiment monitoring the change in mass, C- and N concentrations of a variety of charcoal types in a Norwegian boreal forest over a period of 20 months. The charcoal types represent different feedstock tree species, production temperature regimes, and placements in the forest, i.e. above ground, in the humus layer or in contact with the mineral subsoil. The types of charcoal had different initial C concentrations mainly depending on their production temperature. Nevertheless, all types of charcoal at all placements in the forest showed an initial drop in their C concentrations, which subsequently rose back to reach near initial values in part of the charcoal types. In part of the charcoal types, N concentrations decreased throughout the experiment, exhibiting considerable variation among feedstock species, production temperature regime, and placements in the forest. C/N ratios rose especially in charcoal made from wood of Scots pine (Pinus sylvestris L.), and charcoal that had been stored in contact with the mineral subsoil showed the most rapid mass gain. Our results confirm the important influence of production temperature and feedstock type on the degradation of charcoal, but they also show that microbial activity and environmental conditions play significant roles in charcoal degradation and thus for the fate of pyrogenic carbon under natural conditions.  相似文献   

Changes in soil organic carbon and nitrogen in an area of Andisol following afforestation with Japanese cedar and Hinoki cypress     

《Soil Science and Plant Nutrition》2013,59(2):332-343

Abstract

To determine the rates of increase in C and N stocks in the soil and organic layers following afforestation in Andisols, we measured C and N densities in the organic and soil layers at depths of 0–5, 5–15 and 15–30?cm, together with a chronosequence analysis of 4-year-old, 14-year-old and 23-year-old Japanese cedar (Cryptomeria japonica) and 4-year-old, 12-year-old and 25-year-old Hinoki cypress (Chamaecyparis obtusa) plantations. The short-term changes in C and N were confirmed by repeated sampling 5?years after the first sampling. Tree growth, biomass accumulation and organic layers were much greater in Japanese cedar than in Hinoki cypress plantations. Soil C density (kg?m^?3) increased and bulk density decreased with stand age in the surface layer (0–5?cm). The average soil C accumulation rate was 22.9?g?C?m^?2?year^?1 for Japanese cedar and 21.1?g?C?m^?2?year^?1 for Hinoki cypress. Repeated sampling showed that the rate of increase in C in the surface soil was relatively slow in young stands and that soil C density (kg?m^?3) in the subsurface soil did not change over a 5-year period. Although N accumulated in the tree biomass and organic layers, the soil N density (kg?m^?3) did not change after afforestation. Although the andic properties of the soil and differences in the planted species did not influence the rate of increase in soil C, soil C density was expected to increase to a concentration greater than 80?g?kg^?1, possibly because of the large C accumulation capacity of Andisols.  相似文献   

祁连山南麓高寒灌丛GPP变化特征及对生长季积温的响应     

祝景彬  贺慧丹  李红琴  张法伟  李英年  杨永胜  张光茹  王春雨  罗方林 《草业科学》2021,(2):221-230

全球气候变化背景下气温逐渐升高,将会对陆地生态系统碳循环产生重要影响。研究利用2003?2016年的涡度相关系统观测资料,研究了祁连山南麓高寒灌丛生长季(5月?9月)总初级生产力(gross primary productivity,GPP)在不同时间尺度上对生长季有效积温(growing season degree days,GDD)的响应,对于研究气候变暖对高寒生态系统碳循环的影响有重要意义。结果表明:高寒灌丛生态系统在生长季的月GPP、GDD都表现为先增大后减小的单峰变化趋势,都在7月或8月达到峰值,在5月达到最小值。在整个生长季尺度上,GPP与GDD具有较高变异性,但整体上表现为逐渐增加的趋势(P<0.05)。2003?2016年整个生长季GPP与GDD的均值分别为507.11 g·m^?2和975.93℃。在月尺度和生长季尺度上,GPP与GDD都呈显著正相关关系(P<0.05)。但是,通过比较生长季每个月GPP与GDD的关系发现,5、9月的GPP与GDD没有显著相关性(P>0.05),而在7月相关性最为显著(P<0.01)。整体上看,高寒灌丛生态系统植被的总初级生产力与热量条件表现为正相关关系,由此说明在全球气候变暖的背景下,青藏高原高寒灌丛生态系统植被的光合生产能力将会提高。  相似文献