How do we cultivate in England? Tillage practices in crop production systems

Reducing tillage intensity offers the possibility of moving towards sustainable intensification objectives. Reduced tillage (RT) practices, where the plough is not used, can provide a number of environmental and financial benefits, particularly for soil erosion control. Based on 2010 harvest year data from the nationally stratified Farm Business Survey and drawing on a sub‐sample of 249 English arable farmers, we estimate that approximately 32% of arable land was established under RT, with 46% of farms using some form of RT. Farms more likely to use some form of RT were larger, located in the East Midlands and South East of England and classified as ‘Cereals’ farms. Application of RT techniques was not determined by the age or education level of the farmer. Individual crops impacted the choice of land preparation, with wheat and oilseed rape being more frequently planted after RT than field beans and root crops, which were almost always planted after ploughing. This result suggests there can be limitations to the applicability of RT. Average tillage depth was only slightly shallower for RT practices than ploughing, suggesting that the predominant RT practices are quite demanding in their energy use. Policy makers seeking to increase sustainable RT uptake will need to address farm‐level capital investment constraints and target policies on farms growing crops, such as wheat and oilseed rape, that are better suited to RT practices.     

The role of social capital in the promotion of conservation farming: the case of ‘landcare’ in the Southern Philippines

‘Social capital’ refers to the relationships of trust, communication, and cooperation that facilitate collective action in a community. It is particularly relevant to soil conservation in developing countries, which requires collective efforts to raise awareness of soil degradation, provide effective training in soil conservation practices, and implement soil conservation measures on individual farms. The Landcare Program in the Southern Philippines promotes simple conservation practices in upland environments through establishing and supporting community landcare groups and municipal landcare associations, thus augmenting the social capital of farmers in these locations. An evaluation of the Landcare Program in Barangay Ned, South Cotabato, based on a survey of 313 farm households and case studies of nine landcare groups, shows that, despite extreme isolation and difficult working conditions, farmers responded by rapidly forming landcare groups and a landcare association, and adopting contour barriers on their maize farms. They utilized the bonding social capital inhering in their local communities to build stocks of bridging social capital, linking them to information, training and resources from outside their immediate locality. A logistic regression model of the factors affecting adoption of contour barriers shows that farmers who had undergone the practical, farmer‐based training provided by the Landcare Program, and who were members of a landcare group, were significantly more likely to adopt conservation measures. These results confirm the value of investing in social capital to promote soil conservation. Copyright © 2005 John Wiley & Sons, Ltd.     

Network‐based approaches for soil health research and extension programming in North Dakota,USA

Farmer adoption of practices to build soil health can be enhanced using a knowledge network supported by programs and resources that incorporate technical, social and experiential learning pathways. University Extension plays a critical role in building and supporting the knowledge network by serving as (a) a boundary organization to create space for conversations to occur, (b) network manager to facilitate learning and (c) builder of social capital to encourage trust in the network. The North Dakota State University (NDSU) Soil Health Program was used to illustrate the above approach. Between 2014 and 2016, 32 informal discussion groups, called Soil Health Café Talks, reached 156 individuals. A knowledge network of all participants was developed using NodeXL. The 10 most influential individuals in the network included two scientists, five farmers, one crop consultant and two Extension specialists. All non‐NDSU participants received an evaluation form. Respondents increased their frequency of discussing cover crops with other individuals and increased sharing equipment across farming operations (i.e., vertical tillage implements and no‐till drills). Of the topics discussed, over 25% of respondents adopted practices using cover crops (interseeding and using cover crops for weed control and adjusting rotations to incorporate cover crops) as a result of attending Café Talks. Respondents also increased their use of NDSU Soil Health online resources such as Twitter (22%), YouTube (23%) and the web page (21%) as follow‐up information to Café Talks. Network‐based approaches have proven to be successful in encouraging on‐farm adoption of soil health‐building practices.     

Carbon sequestration and saving potential associated with changes to the management of agricultural soils in England

Abstract. The potential for soil organic carbon sequestration, energy savings and the reduction of the emission of greenhouse gases were investigated for a range of changes in the management of tilled land and managed grassland. These parameters were modelled on a regional basis, according to local soils and crop rotations in England, and avoided the use of soil related indices. The largest carbon sequestration and saving contribution possible comes from an increase in the proportion of permanent woodland, such that a 10% change in land use could amount to 9 Mt C yr⁻¹ in the initial years (arable and grassland). Changes in arable management could make a significant contribution to an abatement strategy if carried out in concert with greater use of permanent conservation field margins, increased returns of crop residues and reduced tillage systems, contributing 1.3 Mt C yr⁻¹ in the initial years. It should be noted, however, that true soil carbon sequestration would be only a minor component of this (125 kt C yr⁻¹), the main part being savings on CO₂ emissions from reduced energy use, and lower N₂O emissions from reduced use of inorganic nitrogen fertilizer.     

Crop production through conservation-effective tillage in the tropics

Agriculture can be intensified and food production increased in the tropics through conservation-effective tillage, with other benefits being soil and water conservation, energy saving and improved timeliness of planting.

The agronomic and economic performance of conservation-effective tillage is extremely location-specific. Problems important in semi-arid regions may not be significant in humid tropical areas. This paper attempts to avoid broad generalizations and to indicate ways of developing the best combination of practices for each local situation. The widespread use of on-farm research and demonstration plots to obtain site-specific information would aid the rapid adaptation and adoption of conservation farming practices in developing countries within different regions. Acceptance of conservation tillage by small farmers in developing countries would be an evolutionary process, and their adoption of improved simple farm equipment and appropriate practices to control weeds should be intesively promoted.

A concerted effort to understand and respond to the needs of farmers, crops and soils will be essential in achieving the goal of increasing agricultural productivity while maintaining oil through conservation-effective tillage in the tropics.     

Public Views on Family and Corporate Farms

ABSTRACT

Contemporary agricultural practices and the public's understanding of the same are not necessarily in synchrony. Beliefs about the economic contribution of agriculture, farming practices, and their impacts on the environment and community, and the motivations of farmers were explored via a mail survey of Illinois residents. Respondents were asked to consider farms by structure and describe what they perceive to be attributes or behaviors differentiating family or corporate farms. Respondents recognized the value of agriculture to the state. Overall, agriculture was ranked among the seven standard industry categories as that with the most important economic impact. However, this sector was ranked lower by residents in counties with or adjacent to population centers of a hundred thousand residents or more and by the non farm population. Although perceived distinctions between crop and livestock operations were not substantial, strong differences were perceived between corporate and family farms. Perceived factors differentiating the two farm types included ownership, operation size, business motivation, separation of management and labor, operator's concern for and participation with the local community and environment, heritage, source of labor, and locale of residence. Family farms were perceived in a much more favorable light than their corporate counterparts.     

Economic benefits of conservation tillage in New Zealand I. Mixed crop and livestock farms

Conservation tillage in New Zealand has allowed mixed crop and livestock farmers to adjust their management systems and, potentially, gain significant financial benefits over conventional management practices. Cost savings in machinery and labor were examined and changes in management to prolong livestock grazing are described. As the benefits could only be correctly estimated in an integrated whole farm management system, a typical New Zealand mixed crop and livestock representative farm was used as the background for the analysis. The benefits which arise through adjustments to the farm management system when conservation tillage techniques are effected are shown to be sufficient to affect the management of most New Zealand mixed crop and livestock farms.     

Dryland corn response to tillage and nitrogen fertilization. II. P,K, CA,MG

Abstract

Nitrogen fertilization and tillage practices may influence the availability and uptake of essential plant nutrients other than N. This study was conducted to assess the interactive effects of N rate and timing and tillage practices on uptake and concentration of P, K, Ca and Mg in corn grown under dryland conditions. Potassium accumulations in no till (NT) soils were greater than in conventional till (CT) near the surface and lower than CT in the subsoil. Phosphorus and Ca levels decreased with soil depth, while Mg tended to accumulate in the subsoil. Phosphorus uptake and concentration of 5‐leaf stage corn was increased as tillage intensity decreased. Nitrogen rate at planting increased 5‐leaf P uptake but reduced P concentration; however, by silking no effect of tillage or N fertilization practice on ear leaf P concentration was obtained. Increases in 5‐leaf corn K uptake and concentration as tillage intensity decreased may have reduced Mg and Ca concentrations via cation antagonism. Ear leaf Mg and Ca concentrations were increased by N rate, probably as a result of solubilization of Ca and Mg and improved crop growth. Distribution of essential elements in the soil due to tillage in combination with varying N fertilization practices can influence temporal nutrient uptake, thereby altering plant nutrient diagnosis.     

Is conservation tillage suitable for organic farming? A review

Conservation tillage covers a range of tillage practices, mostly non‐inversion, which aim to conserve soil moisture and reduce soil erosion by leaving more than one‐third of the soil surface covered by crop residues. Organic farmers are encouraged to adopt conservation tillage to preserve soil quality and fertility and to prevent soil degradation – mainly erosion and compaction. The potential advantages of conservation tillage in organic farming are reduced erosion, greater macroporosity in the soil surface due to larger number of earthworms, more microbial activity and carbon storage, less run‐off and leaching of nutrients, reduced fuel use and faster tillage. The disadvantages of conservation tillage in organic farming are greater pressure from grass weeds, less suitable than ploughing for poorly drained, unstable soils or high rainfall areas, restricted N availability and restricted crop choice. The success of conservation tillage in organic farming hinges on the choice of crop rotation to ensure weed and disease control and nitrogen availability. Rotation of tillage depth according to crop type, in conjunction with compaction control measures is also required. A high standard of management is required, tailored to local soil and site conditions. Innovative approaches for the application of conservation tillage, such as perennial mulches, mechanical control of cover crops, rotational tillage and controlled traffic, require further practical assessment.     

Farmer field preparation and tillage practices. Implications for fertilizer technology research

The purpose of this paper is to show how information from diagnostic research on small farmer decision-making about land preparation and tillage pratices may be integrated into experimental research on the design and evaluation of fertilizer technology. Analysis of different land preparation and tillage practices used by farmers in cassava production in Cauca department, Colombia is utilized to develop a model of farmers' decision-making in the choice of tillage techniques.

The decision model indicates that manual tillage practices which involve only partial field tillage are a response to relatively fixed constraints, which imply that it may be difficult for farmers facing these constraints to adopt fertilizer technology which requires full field tillage. Variables associated with choice of tillage method are identified and related to implications for experimental evaluation of fertilizer technology and the distribution of benefits from this research. The findings illustrate that diagnostic research on the agro-socioeconomic constraints faced by small farmers can alert researchers to limiting factors which require recognition in the design and testing of agricultural technology, in order to facilitate rapid and effective adoption by a majority of small farmers.     

Characterizing farming systems around Kakamega Forest,Western Kenya,for targeting soil fertility–enhancing technologies

Kakamega district in Western Kenya represents the smallholder farming systems typical for much of the densely populated humid highlands in East Africa. A specific feature, however, is the presence of a protected forest reserve (Kakamega Forest National Park), covering some 20% of the district area. Year‐round crop production with little use of external inputs is resulting in declining soil fertility and crop yields. Technologies to counteract fertility constraints are rarely implemented, as they do not consider system diversity or farm‐specific characteristics. We surmised that farm type–specific targeting of technology options to address soil fertility–related production constraints would reduce the anthropogenic pressure on the resources of the adjacent Kakamega rainforest reserve. Based on Kenyan national census data, we selected 168 farms in physical proximity of the Kakamega forest and characterized them regarding production system and soil attributes. Cluster and principal component analyses identified five distinct farm categories. Three representative farms from each cluster group were subsequently selected to establish labor‐use patterns, draw resource‐flow maps, and determine NPK balances. Small subsistence‐oriented farms were most common (> 50%), with maize yields of 0.9 t ha^–1 (Cluster 1). Most farmers relied on the forest to provide fire wood, animal feed, and medicinal plants. Mixed farms, combining subsistence maize with industrial crops, were differentiated by soil type, with tea being grown on Ferralsol (Cluster 3), and sugar cane being grown on Acrisol (cluster 4). The dependence on forest resources was limited to animal grazing and the collection of feed stuff (Cluster 3), or the extraction of medicinal plants (Cluster 4). Only few farms showed a high degree of market orientation of the food‐crop production. These comprised either small farms with high investments in fertilizer and maize yields close to 2 t ha^–1 (Cluster 2), or larger farms (1.6–3.9 ha) with low fertilizer but high hired‐labor use (Cluster 5). Their reliance on forest resources was generally low. Resource flows showed mainly patterns of nutrient export in subsistence farms, and more complex flow patterns, involving several farm compartments, in the diversified farms. Partial nutrient balances were strongly negative for N and K, irrespective of soil or farm type. Soil‐fertility characteristics reflected the nutrient balances with generally low C and N in all farms on Acrisol, and low P in farms not applying mineral fertilizers or farmyard manure. The proposed typology is expected to improve the targeting of technologies addressing soil fertility–related production constraints, and to reduce the pressure on forest resources. This is of particular importance in the case of small‐scale subsistence and mixed farms close to the forest margin.     

Economics of reduced tillage for cereal and legume production on rainfed farm enterprises of different sizes in semiarid conditions

Rainfed crop yields are low in semiarid central Spain because precipitation is limited and highly variable. Under these circumstances, producers have to adopt alternative tillage systems that convey a reduction in their unit costs of production to offset the continuous decline in commodity prices. Farmers respond to this situation in essentially two ways: there is a growing interest in adopting reduced tillage systems for seedbed preparation, and a trend to enlarge enterprises by acquiring more arable land either as ownership or tenancy. The objective of the present study was to assess, in semiarid conditions of central Spain, the economic feasibility of chisel ploughing (CP) and no-tillage (NT) systems compared to mouldboard ploughing (MP) for rainfed winter wheat (Triticum aestivum L.) and forage legume, either vetch (Vicia sativa L.) or pea (Pisum sativum L.), production on different farm sizes ranging from 100 to 1600 ha. A decision support system was used to solve for the least-cost machinery selection for each farm enterprise and tillage system considered. No differences were observed in either wheat or forage vetch crop yields averaged across several years, irrespective of the tillage system used. The economic performance was found to depend on the tillage system adopted and farm size. On average fuel consumption was 23% lower in CP and 62% in NT than in MP. Total variable unitary costs were 3.7 and 5.6% lower in CP and NT than in MP. The cost of herbicides in NT was €7.6 ha⁻¹ year⁻¹ higher than in MP and CP. Average unitary gross margins were 11.9 and 10.8% higher in NT than in MP and CP, respectively. If revenues were considered similar in the three tillage systems, MP would still exhibit the poorest economic results in all farm sizes, while CP performance would improve NT values in farm sizes with 200 ha, or less, of arable land. NT was clearly the most profitable system on farms with 400 ha or more of arable land. The 400 ha farm enterprise was observed to mark the breakeven point between the two reduced tillage systems, since up to that size CP was found to provide a better economic performance than NT.     

Modification of porespace by tillage in two stagnogley soils with contrasting management histories

The soil porespace was studied in two long-term tillage experiments on two clayey stagnogleys in Southern England. The soils differed in respect of mineral and organic composition and previous management history. In both soils the total volume of pores and the volume fraction of macropores in the topsoil horizon declined with direct drilling compared with annual ploughing. This difference between tillage treatments appeared to develop more slowly in the soil that was formerly under continuous arable cultivation than in the soil that was previously in long-term grassland. Fluid transport coefficients were greater in ploughed topsoil in both soils; however, at the boundaries between topsoil and subsoil, and in the upper subsoil, permeability and gaseous diffusivity were greater after direct drilling. At a long-term arable site, soil was more consolidated below the depth of ploughing or shallow tillage, whereas in a former grassland soil ploughing disrupted the continuity of channel-type macropores.     

Tillage methods and soil and water conservation methods in the Caribbean

This review describes the tillage methods and soil conservation methods currently utilized in the Commonwealth Caribbean on a range of slopes. A high percentage of the land has slopes which exceed 20° minimum. In these circumstances, tillage is carried out with hand tools and frequently combined with conservation contour drains or/and barriers of cut vegetation laid across the contour. Many farmers form ridges and furrows on the contour with hand tools and a significant number do not use any conservation measures. Tillage, on flat or gently sloping land, is done largely by tractor drawn implements and the tillage method is mainly determined by the crop to be grown and the soil type. The tillage methods used for the cultivation of sugar cane, rice, banana, vegetables and other small row crops are described. The agronomic, cultural and engineering practices used to conserve the soil against water erosion are also described.     

Effects of organic versus conventional management on chemical and biological parameters in agricultural soils

A comparative study of organic and conventional arable farming systems was conducted in The Netherlands to determine the effect of management practices on chemical and biological soil properties and soil health. Soils from thirteen accredited organic farms and conventionally managed neighboring farms were analyzed using a polyphasic approach combining traditional soil analysis, culture-dependent and independent microbiological analyses, a nematode community analysis and an enquiry about different management practices among the farmers. Organic management, known primarily for the abstinence of artificial fertilizers and pesticides, resulted in significantly lower levels of both nitrate and total soluble nitrogen in the soil, higher numbers of bacteria of different trophic groups, as well as larger species richness in both bacteria and nematode communities and more resilience to a drying–rewetting disturbance in the soil. The organic farmers plough their fields less deeply and tend to apply more organic carbon to their fields, but this did not result in a significantly higher organic carbon content in their soils. The levels of ammonium, organic nitrogen, phosphate and total phosphorus did not differ, significantly between the soils under different management. Fifty percent of the conventional Dutch farmers also used organic fertilizers and the numbers of farmers using a green crop fertilizer did not differ between the two management types. Soil type – clayey or sandy soil – in general had a much stronger effect on the soil characteristics than management type. The soil type influenced pH, nitrate, ammonium, phosphate and organic carbon levels as well as numbers of oligotrophic bacteria and of different groups of nematodes, and different diversity indices. With the collected data set certain soil characteristics could also be attributed to the use of different management practices like plow depth, crop or cover crop type or to the management history of the soil.     

轮耕对双季稻田土壤结构及水贮量的影响

该文针对南方稻田长期免耕存在的耕层变浅、下层土壤紧实等问题,进行了土壤轮耕效应的研究。试验选择双季稻区连续7 a免耕稻田,2006年4月设置免耕、翻耕和旋耕3种耕作处理。2007年4月将翻耕、旋耕稻田一半免耕,剩下一半继续翻耕、旋耕。每年早稻和晚稻采用同一耕作措施。研究结果表明,长期免耕表层0～5 cm土壤体积质量呈降低趋势,而下层10～20 cm呈增加趋势。翻耕、旋耕相对于长期免耕能够有效降低下层土壤体积质量,同时,提高下层毛管孔隙度。翻耕、旋耕后免耕下层土壤体积质量呈增加趋势,而毛管孔隙度呈降低趋势。长期免耕后,翻耕、旋耕能够有效增加耕层（0～20 cm）土壤水贮量,特别是在土壤含水率偏低时尤为显著,2007年翻耕、旋耕较长期免耕分别高了12.9%和20.7%,而翻耕、旋耕后免耕呈降低趋势。研究还显示,各轮耕耕层土壤质量含水率与体积质量呈显著线性负相关,与毛管孔隙度呈显著线性正相关。总之,长期免耕后,翻耕、旋耕措施通过改变耕层土壤结构,进而提高稻田土壤水贮量。     

Influence of reduced tillage on earthworm and microbial communities under organic arable farming

Although reduced tillage is an agricultural practice reported to decrease soil erosion and external inputs while enhancing soil fertility, it has still rarely been adopted by European organic farmers. The objective of this study was to assess the long-term interactive effects of tillage (conventional (CT) vs. reduced (RT)) and fertilization (slurry (S) vs. composted manure/slurry (MCS)) on earthworms and microbial communities in a clay soil under spelt in an organic 6-year crop rotation. Earthworm populations (species, density and biomass, cocoons) were investigated by handsorting the soil nine years after initial implementation of the treatments. Soil microbial carbon (C_mic) and nitrogen (N_mic) were measured by chloroform-fumigation extraction and a simplified phospholipid fatty acid (PLFA) analysis was used to separate for populations of bacteria, fungi and protozoa. Significantly increased total earthworm density in RT plots was mainly attributed to increased numbers of juveniles. Moreover, we found five times more cocoons with RT. Species richness was not affected by the treatments, but tillage treatments had differentially affected populations at the species-level. In addition, cluster analysis at the community level revealed two distinct groups of plots in relation to tillage treatments. In RT plots C_mic increased in the 0–10 cm and 10–20 cm soil layers, while PLFA concentrations indicative of Gram-negative bacteria, fungi and protozoa only increased in the topsoil. Lower bacteria-to-fungi ratios in the upper soil layer of RT plots indicated a shift to fungal-based decomposition of organic matter whereas a higher C_mic-to-C_org ratio pointed towards enhanced substrate availability. Slurry application decreased microbial biomass and enhanced density of juvenile anecic earthworms but overall fertilization effect was weak and no interactions with tillage were found. In conclusion, tillage is a major driver in altering communities of earthworms and microorganisms in arable soils. The use of reduced tillage provides an approach for eco-intensification by enhancing inherent soil biota functions under organic arable farming.     

Soil microbial diversity and activity in a Mediterranean olive orchard using sustainable agricultural practices

Sustainable soil management of orchards can have positive effects on both soils and crop yields due to increases in microbial biomass, activity and complexity. The aim of this study was to investigate medium‐term effects (12 yr) of two different management practices termed ‘sustainable’ (ST) and ‘conventional’ (CT) on soil microbial composition and metabolic diversity of a rainfed mature olive orchard in Southern Italy. ST included no‐till, self‐seeding weeds (mainly graminaceous and leguminosae), and mulch derived from olive tree prunings, whilst CT was managed by frequent tillage and included severe pruning with residues removed from the orchard. Microbial analyses were carried out by culture‐dependent methods (microbial cultures and Biolog^®). Molecular methods were used to confirm the identification by light microscopy of the isolates of fungi and Streptomyces. Significantly more culturable fungi and bacteria were found in ST than in CT. The number of fungal groups in ST was also significantly greater than in CT. Overall and substrate‐specific Biolog^® metabolic diversity indices of microbial communities and soil enzyme activities were greater in ST. The results demonstrate that soil micro‐organisms respond positively to sustainable orchard management characterized by periodic applications of locally derived organic matter. This study confirms the need to encourage farmers with orchards in the Mediterranean basin to practise soil management based on organic matter inputs associated with zero tillage to improve soil functionality.     

耕作对坡耕地水土流失和冬小麦产量的影响

在模拟降雨和自然降雨条件下研究长期（6年）定位耕作措施对豫西早区坡耕地水分保持、土壤流失以及冬小麦产量的影响。耕作措施包括少耕、免耕覆盖、深松覆盖和常规耕作。田间模拟降雨试验用来测定不同耕作措施对径流和土壤流失的影响，自然降雨小区主要用来验证模拟试验结果，同时测定不同耕作措施对冬小麦产量的影响。模拟试验结果表明：不同耕作措施下的土壤饱和导水率没有明显差异，雨前土壤含水量和降雨强度均显著影响地表径流。在试验条件下，免耕覆盖处理未产生径流和土壤流失，水土保持效果最好。与常规耕作比较，深松覆盖处理分别减少径流和土壤流失50％和90％。尽管少耕可以有效降低土壤流失，但其产生的径流量和常规耕作相近。在自然降雨条件下，免耕覆盖和深松覆盖的水土保持效果从第3年开始显著。深松覆盖在任何年型均能够显著提高冬小麦的产量。相比较常规耕作，深松覆盖平均增产9．4％。免耕覆盖除丰水年也能显著提高冬小麦产量．但增产效果不如深松覆盖显著。少耕无明显增产效果。由于产量对农民来说是评判一个耕作措施效果的重要依据，同时考虑到深松覆盖显著的水土保持效果，我们认为深松覆盖是适合当地早作农业的一个有效耕作措施。