Increase in maize yield and soil aggregate-associated carbon in North China due to long-term conservation tillage

2021 ◽  
pp. 1-12
Author(s):  
Ying Shen ◽  
Tingting Zhang ◽  
Jichao Cui ◽  
Siyu Chen ◽  
Huifang Han ◽  
...  

Summary The North China Plain (NCP) is an important agricultural area, where conventional tillage (CT) is used year-round. However, long-term CT has damaged the soil structure, threatening agricultural sustainability. Since 2002, we have conducted a long-term tillage experiment in the NCP to explore the effects of different types of tillage on soil and crop yield. As part of long-term conservation tillage, we conducted a 2-year study in 2016/2017 to determine the impact of no tillage (NT), subsoiling (SS), rotary tillage (RT) and CT on soil aggregate distribution, aggregate-associated organic carbon (AOC), aggregate-associated microbial biomass carbon (AMBC), and maize yield. Compared to CT, NT increased the content of macro-aggregates (+4.8%), aggregate-AOC (+8.3%), and aggregate-AMBC (+18.3%), but decreased maize yield (−11.5%). SS increased the contents of macro-aggregates (+5%), aggregate-AOC (+14.7%), and aggregate-AMBC (+16%); although the yield increase was not significant (+0.22%), it had the highest economic benefit among the four tillage measures. RT had no significant advantage when considering the above soil variables; moreover, it reduced maize yield by 16.1% compared with CT. Overall, SS is a suitable tillage measure to improve soil macro-aggregate content, carbon content, yield, and economic benefit in the NCP area.

CATENA ◽  
2020 ◽  
Vol 188 ◽  
pp. 104428 ◽  
Author(s):  
Zheng-Rong Kan ◽  
Shou-Tian Ma ◽  
Qiu-Yue Liu ◽  
Bing-Yang Liu ◽  
Ahmad Latif Virk ◽  
...  

Agronomy ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 951
Author(s):  
Huayan Zhang ◽  
Ling’an Niu ◽  
Kelin Hu ◽  
Jinmin Hao ◽  
Fan Li ◽  
...  

Agricultural management, such as tillage and straw-returning, affect soil fertility and nutrient cycling in agroecosystems. With the increasing food demand and challenges imposed by climate change, these effects on soil fertility need to be closely monitored, so that short-term agricultural intensification should not threaten the long-term productivity of the land. Therefore, the main objective of this study was to examine the long-term effects of different management practices on soil aggregate stability and associated organic carbon (OC) and nitrogen (N) over a 33-year period in the croplands of the North China Plain. Bulk soils from the surface and subsurface layers were fractionated using the wet sieving approach. The results showed that the silt + clay (SC) fractions (<0.053 mm) were predominant, accounting for 32–56% of the mass at the 0–20 cm depth, and accounting for 41–55% of the mass at the 20–40 cm depth. Additionally, long-term (33 years) no-tillage management and straw-returning at different application rates increased the mass of large soil macroaggregates (LMA), the LMA- and macroaggregate-associated OC content, but decreased the SC-associated OC content. Mineral N and P fertilizers had a minor effect on the stabilization of soil aggregates. The treatment with straw significantly increased the mean weight diameter (MWD) and geometric mean diameter (GWD), compared with the treatment without straw. Our results indicate that carefully regulated management practices would enhance soil aggregate stability, associated OC and N content in the intensive agroecosystem.


PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e11099
Author(s):  
Ying Shen ◽  
Tingting Zhang ◽  
Jichao Cui ◽  
Siyu Chen ◽  
Huifang Han ◽  
...  

Background Soil degradation is one of the main problems in agricultural production and leads to decreases in soil quality and productivity. Improper farming practices speed this process and are therefore not conducive to food security. The North China Plain (NCP) is a key agricultural area that greatly influences food security in China. To explore the effects of different tillage measures on aggregate-associated organic carbon (AOC), the accumulation and transport of dry matter, and maize yield, and to identify the most suitable tillage method for use on the NCP, a field experiment was conducted at Shandong Agricultural University from 2016–2017 using plots that have been farmed using conservation tillage since 2002. Methods In this study, Zhengdan 958 summer maize was used as the test material and undisturbed soil and plant samples were obtained under four tillage methods—no-tillage (NT, tillage depth: 0 cm); rotary tillage (RT, tillage depth: 10 cm); conventional tillage (CT, tillage depth: 20 cm); subsoiling (SS, tillage depth: 40 cm)—which were used to determine the AOC and dry matter contents, as well as the yields of two summer maize growing seasons. Each sample was replicated three times and the AOC content was determined via potassium dichromate oxidation colorimetry. Potassium dichromate oxidized organic carbon in organic matter was employed to reduce hexadecent chromium into green trivalent chromium. Colorimetry was then used to determine the amount of reduced trivalent chromium and calculate the organic matter content. Results The resulting data were statistically analyzed and the results showed that, compared with CT, the AOC contents with NT and SS increased by 5.65% and 9.73%, respectively, while that with RT decreased by 0.12%. Conventional tillage resulted in the highest mean dry matter weight when the maize reached maturity, which was 19.19%, 9.83%, and 3.38% higher than those achieved using NT, RT, and SS, respectively. No significant difference was found between CT and SS treatments, both of which tended to increase the accumulation of dry matter as well as its contribution of assimilates to grain yield post-anthesis. Compared with CT, the mean yield increased at a rate of 0.18% with SS, while yields declined at rates of 17.17% and 11.15 with NT and RT, respectively. The yield with NT was the lowest, though the harvest indices with NT and SS were higher than those with RT and CT. Overall, SS increased the accumulation of dry matter and its contribution of assimilates to grain yields post-anthesis, as well as the AOC content and yields, making it the ideal tillage method for the NCP.


Author(s):  
Robert H. Ellison

Prompted by the convulsions of the late eighteenth century and inspired by the expansion of evangelicalism across the North Atlantic world, Protestant Dissenters from the 1790s eagerly subscribed to a millennial vision of a world transformed through missionary activism and religious revival. Voluntary societies proliferated in the early nineteenth century to spread the gospel and transform society at home and overseas. In doing so, they engaged many thousands of converts who felt the call to share their experience of personal conversion with others. Though social respectability and business methods became a notable feature of Victorian Nonconformity, the religious populism of the earlier period did not disappear and religious revival remained a key component of Dissenting experience. The impact of this revitalization was mixed. On the one hand, growth was not sustained in the long term and, to some extent, involvement in interdenominational activity undermined denominational identity; on the other hand, Nonconformists gained a social and political prominence they had not enjoyed since the middle of the seventeenth century and their efforts laid the basis for the twentieth-century explosion of evangelicalism in Africa, Asia, and South America.


Author(s):  
Weiqi Xu ◽  
Chun Chen ◽  
Yanmei Qiu ◽  
Conghui Xie ◽  
Yunle Chen ◽  
...  

Organic aerosol (OA), a large fraction of fine particles, has a large impact on climate radiative forcing and human health, and the impact depends strongly on size distributions. Here we...


Author(s):  
Yao Li ◽  
Haoyang Li ◽  
Jianqing Ruan

The natural environment is one of the most critical factors that profoundly influences human races. Natural disasters may have enormous effects on individual psychological characteristics. Using China’s long-term historical natural disaster dataset from 1470 to 2000 and data from a household survey in 2012, we explore whether long-term natural disasters affect social trust. We find that there is a statistically significant positive relationship between long-term natural disaster frequency and social trust. We further examine the impact of long-term natural disaster frequency on social trust in specific groups of people. Social trust in neighbors and doctors is stronger where long-term natural disasters are more frequent. Our results are robust after we considering the geographical difference. The effect of long-term natural disasters remains positively significant after we divide the samples based on geographical location. Interestingly, the impact of long-term flood frequency is only significant in the South and the impact of long-term drought frequency is only significant in the North.


2016 ◽  
Author(s):  
X. Long ◽  
X. X. Tie ◽  
J. J. Cao ◽  
R. J. Huang ◽  
T. Feng ◽  
...  

Abstract. Crop field burning (CFB) has important effects on air pollution in China, but it is seldom quantified and reported in a regional scale, which is of great importance for the control strategies of CFB in China, especially in the North China Plain (NCP). With the provincial statistical data and open crop fires captured by satellite (MODIS), we extracted a detailed emission inventory of CFB during a heavy haze event from 6th to 12th October 2014. A regional dynamical and chemical model (WRF-Chem) was applied to investigate the impact of CFB on air pollution in NCP. The model simulations were compared with the in situ measurements of PM2.5 (particular matter with radius less than 2.5 μm) concentrations. The model evaluation shows that the correlation coefficients (R) between measured and calculated values exceeds 0.80 and absolute normalized mean bias (NMB) is no more than 14 %. In addition, the simulated meteorological parameters such as winds and planetary boundary layer height (PBLH) are also in good agreement with observations. The model was intensive used to study (1) the impacts of CFB and (2) the effect of mountains on regional air quality. The results show that the CFB occurred in southern NCP (SNCP) had significant effect on PM2.5 concentrations locally, causing a maximum of 35 % PM2.5 increase in SNCP. Because of south wind condition, the CFB pollution plume is subjective a long transport to northern NCP (NNCP-with several mega cities, including Beijing of the capital city in China), where there are no significant CFB occurrences, causing a maximum of 32 % PM2.5 increase in NNCP. As a result, the heavy haze in Beijing is enhanced by the CFB occurred in SNCP. Further more, there are two major mountains located in the western and northern NCP. Under the south wind condition, these mountains play important roles in enhancing the PM2.5 pollution in NNCP through the blocking and guiding effects. This study suggests that the PM2.5 emissions in SNCP region should be significantly limited in order to reduce the occurrences of heavy haze events in NNCP region, including the Beijing City.


Soil Research ◽  
2001 ◽  
Vol 39 (2) ◽  
pp. 239 ◽  
Author(s):  
Yuxia Li ◽  
J. N. Tullberg ◽  
D. M. Freebairn

Wheel traffic can lead to compaction and degradation of soil physical properties. This study, as part of a study of controlled traffic farming, assessed the impact of compaction from wheel traffic on soil that had not been trafficked for 5 years. A tractor of 40 kN rear axle weight was used to apply traffic at varying wheelslip on a clay soil with varying residue cover to simulate effects of traffic typical of grain production operations in the northern Australian grain belt. A rainfall simulator was used to determine infiltration characteristics. Wheel traffic significantly reduced time to ponding, steady infiltration rate, and total infiltration compared with non-wheeled soil, with or without residue cover. Non-wheeled soil had 4—5 times greater steady infiltration rate than wheeled soil, irrespective of residue cover. Wheelslip greater than 10% further reduced steady infiltration rate and total infiltration compared with that measured for self-propulsion wheeling (3% wheelslip) under residue-protected conditions. Where there was no compaction from wheel traffic, residue cover had a greater effect on infiltration capacity, with steady infiltration rate increasing proportionally with residue cover (R 2 = 0.98). Residue cover, however, had much less effect on inf iltration when wheeling was imposed. These results demonstrated that the infiltration rate for the non-wheeled soil under a controlled traffic zero-till system was similar to that of virgin soil. However, when the soil was wheeled by a medium tractor wheel, infiltration rate was reduced to that of long-term cropped soil. These results suggest that wheel traffic, rather than tillage and cropping, might be the major factor governing infiltration. The exclusion of wheel traffic under a controlled traffic farming system, combined with conservation tillage, provides a way to enhance the sustainability of cropping this soil for improved infiltration, increased plant-available water, and reduced runoff-driven soil erosion.


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Cassandra R. Davis ◽  
Sarah R. Cannon ◽  
Sarah C. Fuller

PurposeThe purpose of this paper is to identify and describe the long-term impacts of hurricanes on schools and discuss approaches to improving recovery efforts.Design/methodology/approachInterviews with 20 school districts in Texas and North Carolina after Hurricanes Harvey (2017) and Matthew (2016). In total, 115 interviews were conducted with teachers, principals, district superintendents and representatives from state education agencies. Interview questions focused on the impact of storms and strategies for recovery.FindingsThe authors uncovered three long-term impacts of hurricanes on schools: (1) constrained instructional time, (2) increased social-emotional needs and (3) the need to support educators.Research limitations/implicationsThis paper focuses on two storms, in two states, in two successive years. Data collection occurred in Texas, one academic year after the storm. As compared to the North Carolina, data collection occurred almost two academic years after the storm.Practical implicationsThis paper illuminates strategies for stakeholders to implement and expedite hurricane recovery through; (1) updating curricula plans, (2) providing long-term counselors and (3) supporting educators in and out of school.Originality/valueTo date, very few studies have explored the ways in which schools face long-term impacts following a disaster. This paper provides insight to the challenges that prolong the impacts of disasters and impede recovery in schools. With hurricanes and related disasters continuing to affect schooling communities, more research is needed to identify the best ways to support schools, months to years after an event.


Sign in / Sign up

Export Citation Format

Share Document