Influence of Conservation Tillage on Soil Aggregates Features in North China Plain

Tillage greatly influences the aggregation and stability of soil aggregates. This study investigated the effects of conservation tillage on soil aggregate characteristics. During a four-year study period （2001-2005）, soils were sampled from no-tillage （NT）, rotary tillage （RT）, and conventional tillage （moldboard tillage, CT） plots at the Luancheng Agriculture and Ecology Experimental Station in Hebei Province, China, and the amount, size distribution, and fractal dimension of the aggregates were examined by dry and wet sieving methods. The results indicated that NT significantly increased the topsoil （0-5 cm） bulk density （BD）, while RT maintained a lower BD as CT. Dry sieving results showed that NT had higher macro-aggregate content （R0.25）, and a larger mean weight diameter （MWD） and geometric mean diameter （GMD） than other treatments in the 0-10 cm layer, while RT showed no difference from CT. In wet sieving, results showed that most of the aggregates were unstable, and the MWD and GMD of water-table aggregates showed the trend of NT 〉 RT 〉 CT. At 0-5 cm layer, the fractal dimension （D） of water-stable aggregates under NT was lower than it was under RT and CT. At 5-10 cm, RT yielded the highest D, and showed stability. After four years, NT increased the aggregation and the stability of soil aggregates; while due to intense disturbance, the aggregation and stability of the upper layer （0-10 cm） under RT and CT decreased.

Effects of Conservation Tillage on Crop Yield: a Case Study in the Part of Typical Ecological Zones in China

To evaluate the effects of different conservation tillage modes on crop yield in various ecological regions, we interviewed peasant households in the Northeast China Plain, North China Plain, Chengdu Plain, and Northwest China Oasis, China, to analyze the influencing factors of the tillage methods on crop yield. An index set was determined from seven yield parameters based on expert consultation and relevant literature. A comprehensive evaluation of conservation tillage methods in the various ecological regions was carried out using fuzzy theory. The approaches with the highest scores were identified for each region： wide and narrow rotation planting with high stubble standing retention in the Northeast China Plain; seeding after rotary tilled of wheat under corn straw mulching and no-tillage seeding of corn and other crops under wheat straw mulching in the North China Plain; no tillage with high stubble retention in the Northwest China Oasis; and no-tillage seeding of wheat and other crops under rice straw mulching in Chengdu Plain. These research data provide a useful guide for the selection of conservation tillage methods for optimum yields in different regions of China.

Analysis of Soil Fertility and Biological Changes under Long-term Conservation Tillage

Compared with traditional tillage,the farmland soil ecosystem realizes increase in the number and diversity of soil microorganisms and animal communities. The conservation tillage measures such as no-tillage( zero tillage) and covering the farmland with organic matters reduce the disturbance to the soil,increase the accumulation of soil organic matter,and provide an excellent microhabitat for the biological activity of the soil. Soil organisms are closely related to soil nutrient movement. Soil animals,soil microorganisms and soil enzymes secreted by them are widely involved in the conversion process of organic matters and mineral nutrients,and they also play an important role in the effectiveness of nutrient utilization. Studies have shown that long-term conservation tillage is favorable for improving the soil biological activity,improving the soil health,and increasing the fertilizer utilization efficiency and the conservation in soil.

Influences of wide-narrow seeding on soil properties and winter wheat yields under conservation tillage in North China Plain

In order to promote the winter wheat yield and guarantee seeding quality in double-cropping system,no-tillage or reduced tillage planting modes with different row spacing have been implemented to result in different levels of yield.A three-year(2012-2015)field experiment was conducted on the experimental farm at Zhuozhou of Hebei Province in North China Plain to compare winter wheat yield from the two planting modes:wide-narrow row space planting mode(WN)and uniform row space planting mode(UR)Both planting modes were performed under reduced tillage conditions with straw mulching.The results showed that in North China Plain WN had positive impacts on crop yield,yield components,leaf area index(LAI)and intercepted photosynthetically active radiation(IPAR)index.Comparing with the UR,IPAR and LAI index for WN were enhanced by 4.8%and 5.2%,respectively.The average yield for WN was 7.2%,significantly greater than that of UR under the same quantity and density.In addition,for WN mode,machinery could pass through with less blocking under large amount of straw mulching,which largely improved tillage efficiency and potentially popularized the conservation tillage technology in North China plain.It is therefore recommended that wide-narrow row space planting mode(WN)combined with reduced tillage and straw mulching be more suitable for conservation tillage in double-cropping pattern areas in North China Plain.

Conservation tillage impacts on soil,crop and the environment

There is an urgent need to match food production with increasing world population through identification of sustainable land management strategies.However,the struggle to achieve food security should be carried out keeping in mind the soil where the crops are grown and the environment in which the living things survive.Conservation agriculture(CA),practising agriculture in such a way so as to cause minimum damage to the environment,is being advocated at a large scale world-wide.Conservation tillage,the most important aspect of CA,is thought to take care of the soil health,plant growth and the environment.This paper aims to review the work done on conservation tillage in different agro-ecological regions so as to understand its impact from the perspectives of the soil,the crop and the environment.Research reports have identified several benefits of conservation tillage over conventional tillage(CT)with respect to soil physical,chemical and biological properties as well as crop yields.Not less than 25%of the greenhouse gas effluxes to the atmosphere are attributed to agriculture.Processes of climate change mitigation and adaptation found zero tillage(ZT)to be the most environmental friendly among different tillage techniques.Therefore,conservation tillage involving ZT and minimum tillage which has potential to break the surface compact zone in soil with reduced soil disturbance offers to lead to a better soil environment and crop yield with minimal impact on the environment.&2015 International Research and Training Center on Erosion and Sedimentation and China Water and Power Press.Production and Hosting by Elsevier B.V.This is an open access article under the CC BY-NC-ND license(http://creativecommons.org/licenses/by-nc-nd/4.0/).

Comparison of soil carbon dioxide emission between controlled and random traffic under conservation tillage

Conservation tillage is proven to be a useful agricultural practice for reducing the concentration of CO_(2) released to the atmosphere,but there is currently only limited information regarding the influences of controlled traffic on soil CO_(2) fluxes.Therefore,this study investigated the effects of controlled traffic on soil CO_(2) flux and on fuel consumption in winter wheat(Triticum aestivum L.)and maize(Zea mays L.)croplands of northern China.CO_(2) samples were collected from various compacted areas in the fields,including the crop zone,the inter-row zone and the traffic zone.CO_(2) flux from the soil surface was measured with a GXH-3010E1 CO_(2) infrared analyzer during the crop grain filling stage.CO_(2) fluxes were considerably larger for controlled traffic field(95.04±6.79)g/(m2·d)than that for random traffic field(50.91±7.57)g/(m2·d)in the crop zone,but there were no significant differences between random and controlled traffic fields in the inter-row zone.In contrast,in the traffic zone,all fluxes were lower than those in the other areas.Total CO_(2) fluxes were not significantly different between controlled traffic and random traffic fields.Controlled traffic can reduce fuel consumption by 9.7 L/hm2 compared to random traffic,which implies that it can also reduce the total annual amount of CO_(2) released from agricultural activities.

The development and adoption of conservation tillage systems on the Canadian Prairies

One of the major agricultural innovations on the Canadian Prairies over the last 40 years has been the introduction of conservation tillage(CT).Conservation tillage-a system that includes minimum and zero tillage(ZT)-was introduced as an alternative to traditional(conventional)tillage(TT)to control soil degradation and to promote agricultural sustainability.The development and adoption of CT systems involved pioneer farmers,engineers,scientists,and farmer associations.By the end of the 1970s,CT started to take shape on the Prairies,but for a number of economic,technical,political and social reasons,the adoption of CT did not occur on any major scale before the 1990s.Today,more than 75%of the Prairie’s cropland is under some form of CT with more than 50%under ZT.In this paper,the factors behind the development and adoption of conservation tillage technology on the Prairies in the period between 1930 and 2011 are reviewed.Then,some of the benefits of the adoption of CT on the Prairies are highlighted.The data show that CT and ZT became profitable for the majority of farmers during and after the 1990s,and that the increased use of CT contributed to the dramatic decrease in the area under summerfallow and to the increase in the area sown to canola and pulse crops.These changes contributed to the reduction of all forms of land degradation and to decreases in agricultural greenhouse gas(GHG)emissions.

The effect of conservation tillage on crop yield in China

Traditional agricultural practices have resulted in decreased soil fertility,shortage of water resources and deterioration of agricultural ecological environment,which are seriously affecting grain production.Conservation tillage(CT)research has been developed and applied in China since the 1960s and 1970s,and a series of development policies have been issued by the Chinese government.Recent research and application have shown that CT has positive effects on crop yields in China.According to the data from the Conservation Tillage Research Center(CTRC),Chinese Ministry of Agriculture(MOA),the mean crop yield increase can be at least 4%in double cropping systems in the North China Plain and 6%in single cropping systems in the dryland areas of Northeast and North-west China.Crop yield increase was particularly significant in dryland areas and drought years.The mechanism for the yield increase in CT system can be attributed to enhanced soil water content and improved soil properties.Development strategies have been implemented to accelerate the adoption of CT in China.

Effects of Different Tillage Systems on Soil Properties,Root Growth,Grain Yield,and Water Use Efficiency of Winter Wheat (Triticum aestivum L.) in Arid Northwest China

Studies on root development, soil physical properties, grain yield, and water-use efficiency are important for identifying suitable soil management practices for sustainable crop production. A field experiment was conducted from 2006 through 2008 in arid northwestern China to determine the effects of four tillage systems on soil properties, root development, water-use efficiency, and grain yield of winter wheat （Triticum aestivum L.）. The cultivar Fan 13 was grown under four tillage systems：conventional tillage （CT） without wheat stubble, no-tillage without wheat stubble mulching （NT）, no-tillage with wheat stubble standing （NTSS）, and no-tillage with wheat stubble mulching （NTS）. The soil bulk density （BD） under CT system increased gradually from sowing to harvest, but that in NT, NTSS, and NTS systems had little change. Compared to the CT system, the NTSS and NTS systems improved total soil water storage （0-150 cm） by 6.1-9.6 and 10.5- 15.3% before sowing, and by 2.2-8.9 and 13.0-15.1% after harvest, respectively. The NTSS and NTS systems also increased mean dry root weight density （DRWD） as compared to CT system. The NTS system significantly improved water-use efficiency by 17.2-17.5% and crop yield by 15.6-16.8%, and the NTSS system improved that by 7.8-9.6 and 7.0-12.8%, respectively, compared with the CT system. Our results suggested that Chinese farmers should consider adopting conservation tillage practices in arid northwestern China because of benefits to soil bulk density, water storage, root system, and winter wheat yield.

Benefits of Conservation Agriculture on Soil and Water Conservation and Its Progress in China

Conservation agriculture has been practised for three decades and has been spread widely. There are many nomenclatures surrounding conservation agriculture and differ to each other lightly. Conservation agriculture （CA） is a system approach to soil and water conservation, high crop productivity and profitability, in one word, it is a system approach to sustainable agriculture. Yet, because conservation agriculture is a knowledge-intensive and a complex system to learn and implement, and also because of traditions of intensive cultivation, adoption rates have been low, since to date, only about seven percent of the world＇s arable and permanent cropland area is farmed under conservation agriculture. The practice and wider extention of conservation agriculture thus requires a deeper understanding of its ecological underpinnings in order to manage its various elements for sustainable intensification, where the aim is to conserve soil and water and improve sustainability over the long term. This paper described terms related to conservation agriculture, presented the effects of conservation agriculture on soil and water conservation, crop productivity, progress and adoption of CA worldwide, emphasized obstacles and possible ways to increase CA adoption to accelerate sustainable development of China agriculture.

Effect of Interplanting with Zero Tillage and Straw Manure on Rice Growth and Rice Quality

The interplanting with zero-tillage of rice, i.e. direct sowing rice 10-20 days before wheat harvesting, and remaining about 30-cm high stubble after cutting wheat or rice with no tillage, is a new cultivation technology in wheat-rice rotation system. To study the effects of interplanting with zero tillage and straw manure on rice growth and quality, an experiment was conducted in a wheat-rotation rotation system. Four treatments, i.e. ZIS （Zero-tillage, straw manure and rice interplanting）, Zt （Zero-tillage, no straw manure and rice interplanting）, PTS （Plowing tillage, straw manure and rice transplanting）, and PT （Plowing tillage, no straw manure and rice transplanting）, were used. ZtS reduced plant height, leaf area per plant and the biomass of rice plants, but the biomass accumulation of rice at the late stage was quicker than that under conventional transplanting cultivation. In the first year （2002）, there was no significant difference in rice yield among the four treatments. However, rice yield decreased in interplanting with zero-tillage in the second year （2003）. Compared with the transplanting treatments, the number of filled grains per panicle decreased but l000-grain weight increased in interplanting with zero-tillage, which were the main factors resulting in higher yield, tnterplanting with zero-tillage improved the milling and appearance qualities of rice. The rates of milled and head rice increased while chalky rice rate and chalkiness decreased in interplanting with zero-tillage. Zero-tillage and interplanting also affected rice nutritional and cooking qualities. In 2002, ZIS showed raised protein content, decreased amylose content, softer gel consistency, resulting in improved rice quality. In 2003, zero-tillage and interplanting decreased protein content and showed similar amylose content as compared with transplanting treatments. Moreover, protein content in PTS was obviously increased in comparison with the other three treatments. The rice in interplanting with zero-tillage treatments had higher peak viscosity and breakdown, lower setback, showing better rice taste quality. The straw manure had no significant effect on rice viscosity under interplanting with zero-tillage, but had the negative influence on the rice taste quality under transplanting with plowing tillage.

Soil carbon storage and stratification under different tillage/residue-management practices in double rice cropping system

The importance of soil organic carbon（SOC） sequestration in agricultural soils as climate-change-mitigating strategy has become an area of focus by the scientific community in relation to soil management.This study was conducted to determine the temporal effect of different tillage systems and residue management on distribution, storage and stratification of SOC, and the yield of rice under double rice（Oryza sativa L.） cropping system in the southern China.A tillage experiment was conducted in the southern China during 2005–2011, including plow tillage with residue removed（PT0）, plow tillage with residue retention（PT）, rotary tillage with residue retention（RT）, and no-till with residue retention on the surface（NT）.The soil samples were obtained at the harvesting of late rice in October of 2005, 2007 and 2011.Multiple-year residue return application significantly increased rice yields for the two rice-cropping systems; yields of early and late rice were higher under RT than those under other tillage systems in both years in 2011.Compared with PT0, SOC stocks were increased in soil under NT at 0–5, 5–10, 10–20, and 20–30 cm depths by 33.8, 4.1, 6.6, and 53.3%, respectively, in 2011.SOC stocks under RT were higher than these under other tillage treatments at 0–30 cm depth.SOC stocks in soil under PT were higher than those under PT0 in the 0–5 and 20–30 cm soil layers.Therefore, crop residues played an important role in SOC management, and improvement of soil quality.In the 0–20 cm layer, the stratification ratio（SR） of SOC followed the order NT〉RT〉PT〉PT0; when the 0–30 cm layer was considered, NT also had the highest SR of SOC, but the SR of SOC under PT was higher than that under RT with a multiple-year tillage practice.Therefore, the notion that conservation tillage lead to higher SOC stocks and soil quality than plowed systems requires cautious scrutiny.Nevertheless, some benefits associated with RT system present a greater potential for its adoption in view of the multiple-year environmental sustainability under double rice cropping system in the southern China.

Water Availability for Winter Wheat Affected by Summer Fallow Tillage Practices in Slope Dryland

The tillage experiments for winter wheat were conducted on the slope farmland in Luoyang, Henan Province in the semihumid to arid loess plateau areas of North China. Different tillage methods including reduced tillage(RT), no-till(NT), 2 crops/year(2C), subsoiling(SS), and conventional tillage(CT)were compared to determine the effects of tillage methods on soil water conservation, water availability, and wheat yields in a search for better farming systems in the areas. The NT and SS showed good effects on water conservation. The soil water storage increased 12 - 33 mm with NT and 9-24 mm with SS at the end of summer fallow periods. The soil evaporation with NT and SS decreased 7-8 mm and 34 - 36 mm during the fallow periods of 1999 and 2001, respectively. Evapotranspiration(ET)with NT and SS increased about 47 mm during wheat growth periods of 2000 to 2001. Treatment RT and 2C had low water storage and high water losses during the fallow periods. The winter wheat yields with conservation tillage practices were improved in the 2nd year, increased by 3, 5 and 8% with RT, NT and SS, respectively, compared with CT. The highest wheat yields were obtained with subsoiling, and the maximum economic benefits from no-till. All conservation tillage practices provided great benefits to saving energy and labors, reducing operation inputs, and increasing economic returns. No-till and subsoiling have shown promise in increasing water storage, reducing water loss, enhancing water availability, and saving energy, as well as increasing wheat yield.

Low soil carbon saturation deffcit limits the abundance of cbbL-carrying bacteria under long-term no-tillage maize cultivation in northern China

The responses of cbbL-carrying bacteria to different levels of soil carbon saturation deficits(SCSD)under tillage managements are largely unknown.We assessed the influence of SCSD on the abundance and diversity of cbbLcarrying bacteria under long-term no-tillage with residue retention(NT)and conventional tillage without residue retention(CT)cultivation systems in maize.We found SCSD was smaller under NT than under CT in the 0-15 cm soil layer.The abundance and the Shannon diversity of cbbL-carrying bacteria in the NT treatment were lower than in the CT treatment.Soil carbon saturation and cbbL gene abundance showed a significant positive correlation,but there was no correlation between soil carbon saturation and cbbL gene diversity.However,the long-term NT practice decreased cbbL-carrying bacteria diversity and altered the community structure of the cbbL-carrying bacteria.Our results indicated that low SCSD limited the abundance of cbbL-carrying bacteria,but there was no relationship between low SCSD and diversity of cbbLcarrying bacteria.We suggest that further studies of cbbL-carrying bacteria carbon sequestration rates and capacity should be based on the effect of management practices on cbbL-carrying bacteria abundance and diversity.Our study has important implications for the relationship between the biological and physicochemical mechanisms in CO_(2) fixation.

Spatial variability of soil hydraulic and physical properties in erosive sloping agricultural fields

It is essential to minimize soil quality degradation in sloping agricultural fields through stabilization and improvement of soil hydraulic properties using sustainable soil management.This study aimed to analyze the impact of different tillage practices,including conventional tillage(CT),minimum tillage(MT),and zero tillage(ZT),on soil hydraulic conductivity in a sloping agricultural field under maizeewheat rotation.The results showed that the highest runoff volume(257.40 m3),runoff coefficient(42.84%),and soil loss(11.3 t)were observed when the CT treatment was applied.In contrast,the lowest runoff volume(67.95 m3),runoff coefficient(11.35%),and soil loss(1.05 t)were observed when the ZT treatment was adopted.The soil organic carbon and aggregate mean weight diameter were found to be significantly greater(with mean values of 0.79%and 1.19 mm,respectively)with the ZT treatment than with the CT treatment.With the tilled treatments(CT and MT),substantial changes in the saturated soil hydraulic conductivity(ks),near-saturated soil hydraulic conductivity(k),and water-conducting porosity(ε)were observed between two crop seasons.These three soil parameters were significantly higher in the period after maize harvesting than in the wheat growing period.In contrast,no significant difference in these soil parameters was found when the untilled treatment(ZT)was carried out.With regard to the slope positions,ks,k,andεshowed different behaviors under different treatments.The toe slope position showed significantly lower ks andεvalues than the summit and middle slope positions.Of the evaluated tillage practices,ZT was found to be the most promising means to improve the soil hydro-physical properties and effectively reduce surface runoff and soil erosion.

Developmental Tendency of Dry Land Farming Technologies

The developmental tendency of dry land farming technologies in the semiarid area of China were reviewed based on the overview of recent progress in dry land farming researches from China and oversea. It was emphasized that conservation tillage, limited irrigation, genetic modification and chemical control are the important aspects for the dry land farming research and development of the future. In addition, some consid-

Evaluating spectral indices for determining conservation and conventional tillage systems in a vetch-wheat rotation

Conservation tillage(CT)systems,which consist of reduced and no-tillage systems,retain considerable quantities of crop residues on the soil surface.These crop residues perform as a barrier to wind and water to decrease soil erosion and evaporation.The use of remote sensing technology provides fast,objective and effective tool for estimating and measuring any agricultural event.The challenge is to differentiate the tillage systems by the crop residue cover on the soil surface.Spectrally derived normalized difference tillage index(NDTI),Shortwave infrared normalized difference residue index(SINDRI),cellulose absorption index(CAI)and Lignin-cellulose absorption index(LCA)were examined to distinguish their value as remote sensing methods for identifying crop residue cover in conventional and conservation tillage systems.Tillage treatments included conventional tillage(MD:Mouldboard plow+Disk harrow),reduced tillage(CD:Chisel plowþDisk harrow),minimum till(MT:Stubble cultivator),and no-tillage(NT_(1) and NT_(2):with standing stubble and standing stubble plus threshing residue,respectively).CAI had a linear relationship with crop residue cover,which the comparative intensity of cellulose and lignin absorption features near 2100 nm can be measure by it.Coefficients of determination(r^(2))for crop residue cover as a function of CAI and LCA were 0.89 and 0.79 respectively.Absorption specifications near 2.1 and 2.3 mm in the reflectance spectra of crop residues in minimum and no-tillage systems were related to cellulose and lignin.These specifications were not evident in the spectra of conventional tillage system.In this study the best index to use was CAI,which showed complete separation tillage systems,followed by LCA and NDTI.Four tillage intensity classes,corresponding to intensive(<6%residue cover),reduced(10–20%cover)minimum(25–40%)and no-tillage(>60%cover)tillage,were recognized in this study.

Stalk cutting mechanism of no-tillage planter for wide/narrow row farming mode

A no-tillage planter of narrow row spacing was designed according to the agronomic requirements of wide/narrow row farming mode in the black soil region of Northeast China.Due to the narrow spacing of the seeder unit,a gear-tooth stalk cutting mechanism was designed in order to prevent residues from blocking the planter.The basic parameters,number and edge curve of the stalk cutting blade were designed and optimized.Three-factor and three-level combined orthogonal experiments were conducted using the factors of working speed(1.12 m/s,1.57 m/s and 2.02 m/s),tillage depth(75 mm,90 mm and 105 mm)and cutter spacing(15 mm,30 mm and 45 mm),which significantly affected stalk cutting rate and soil disturbance rate.The optimal combination is the working speed of 1.62 m/s,tillage depth of 92 mm and cutter spacing of 35 mm.Under this condition,the stalk cutting rate is more than 90%and soil disturbance rate is 7.5%-12.0%.The performance of the new no-tillage planter was tested by using the above parameters.The results showed that the no-tillage planter of narrow row spacing came up to the relevant national standards in China.

Review of application of biomimetics for designing soil-engaging tillage implements in Northeast China

The reduction of water resources and soil fertility in Northeast China will have a requirement on higher working efficiency of agricultural soil-engaging components.The adhesion and resistance are main problems for soil-engaging tillage components.However,the soil-burrowing or soil-digging animals give inspirations to resolve those problems.Their fair,claw,toe,textured surface and scales have functions of anti-adhesion or resistance reduction.Those results provide a way to realize the sustainable development of modern agriculture by developing novel biomimetic agricultural machinery systems with independent intellectual property rights to meet conservation tillage requirements in the Northern China region.Biological structures of some soil-burrowing or soil-digging animals,such as beetle,mole cricket,earthworm,mole,vole,pangolin,and snake,as well as their mechanisms of anti-adhesion or reducing resistance were reviewed in this paper.Bioinspired applications in Northeast China were also presented in the paper,including moldboard,subsoiler components,furrow opener,roller,and biomimetic rototilling-stubble-breaking blade.In addition,the existed problems in agricultural engineering and the future development trends were discussed.

Thoughts on developing small/medium size no-till equipment for conservation agriculture in Asia:Summary of post-publication peer review comments

Traditional agriculture bases most of its operations or practices on soil tillage,which causes likely occurrence of water and soil erosion and sediment runoff.In order to conserve soil,water and environment,Conservation agriculture(CA)is increasingly adopted to replace traditional tillage agriculture to achieve sustainable and profitable agriculture and subsequently improve the livelihoods of farmers.CA holds great potential for all sizes of farms and agro-ecological systems,but its adoption is most urgently required by smallholder farmers,especially those short of laborers.Small/medium size no-till machines and implements are the key to CA adoption.A review article on small/medium size no/minimum-till seeders in Asia published in IJABE triggers a lot of scientific conversation on how to develop suitable no-till equipment among peer experts.This paper presents a collection of these post-publication peer review comments including commentary,questions,answers,suggestions,critical thinking,etc.The authors of the review article also provide response,summary of the review comments and their own standpoints.This open post-publication review and commentary may add value to the published review article and provide new ideas useful for future research and development of CA equipment.