Environmentally-sound adaptable tillage – Solutions from Hungary

In the last centuries, the need for tillage was to provide suitable soil conditions for plant growth (crop-focusing tillage). During the last decades, traditional goals of soil tillage have really been improved considering environmental consequences (environment-focusing tillage). In the next decade a new task is stressed, that is mitigating the climate induced losses (climate-focusing tillage). New challenges for the future are prevention of tillage-induced soil quality deterioration, and to reduce climate induced damages by the use of environmentally-sound adaptable tillage. In the adaptable tillage program ten important steps are suggested, namely: (1) Risk assessment in the fields. (2) Prevention of tillage induced defects affecting climate stresses. (3) Maintaining an optimal soil physical and biological state and fertility. (4) Use soil structure conservation methods in any seasons. (5) Mulch the surface at least in summer. (6) Improve soil loading capacity connected with carbon conservation. (7) Utilize stubble residues rationally. (8) Maintain an optimal water management in soils by the soil state improving. (9) Create small water-loss surface at tillage operations. (10) Improve a harmony between soil disturbance and environmental requirements

Manure Incorporation and Reduced Tillage Corn Trial

Timely manure incorporation can reduce nutrient losses to the atmosphere and surface runoff. Keeping valuable nutrients, like nitrogen, in the soil can help reduce the purchase of expensive commercial fertilizers. Reduced tillage corn is becoming more common as growers recognize the benefits to soil health and water quality. There are many options to implement reduced tillage including no-tillage, striptillage, and vertical-tillage, as well as a plethora of strategies and technologies to implement these techniques. No-tillage planting uses metal coulters to cut a slot for the seed, rather than tilling the soil. Strip-tillage opens a strip 8-10” in both directions from the seed slot, warming and drying the soil to aid in corn germination. Vertical-tillage lightly tills the top 2-3” of the soil, as the implement is pulled quickly across a field to produce a uniform seedbed without deep tillage

Manure Incorporation and Reduced Tillage Corn Trial

Timely manure incorporation can reduce nutrient losses to the atmosphere and surface runoff. Keeping valuable nutrients, like nitrogen, in the soil can help reduce the purchase of expensive commercial fertilizers. Reduced tillage corn is becoming more common as growers recognize the benefits to soil health and water quality. Some options to implement reduced tillage include no-tillage and vertical-tillage. No-tillage planting uses metal coulters to cut a slot for the seed, rather than tilling the soil. Vertical-tillage lightly tills the top 2-3” of the soil, as the implement is pulled quickly across a field to produce a uniform seedbed without deep tillage. Little research has been done in the region to assess the combined effects of manure application and reduced tillage practices on silage corn yields and quality. With the increased regional availability of innovative equipment such as manure injectors, aerators, strip tillers, and no-till planters, the University of Vermont Extension’s Northwest Crops & Soils Program designed a trial in 2016 to evaluate both manure incorporation and reduced tillage corn planting techniques on corn yield and quality

Site-Specific Conditions Change the Response of Bacterial Producers of Soil Structure-Stabilizing Agents Such as Exopolysaccarides and Lipopolysaccarides to Tillage Intensity

Agro-ecosystems experience huge losses of land every year due to soil erosion induced by poor agricultural practices such as intensive tillage. Erosion can be minimized by the presence of stable soil aggregates, the formation of which can be promoted by bacteria. Some of these microorganisms have the ability to produce exopolysaccharides and lipopolysaccharides that "glue" soil particles together. However, little is known about the influence of tillage intensity on the bacterial potential to produce these polysaccharides, even though more stable soil aggregates are usually observed under less intense tillage. As the effects of tillage intensity on soil aggregate stability may vary between sites, we hypothesized that the response of polysaccharide-producing bacteria to tillage intensity is also determined by site-specific conditions. To investigate this, we performed a high-throughput shotgun sequencing of DNA extracted from conventionally and reduced tilled soils from three tillage system field trials characterized by different soil parameters. While we confirmed that the impact of tillage intensity on soil aggregates is site-specific, we could connect improved aggregate stability with increased absolute abundance of genes involved in the production of exopolysaccharides and lipopolysaccharides. The potential to produce polysaccharides was generally promoted under reduced tillage due to the increased microbial biomass. We also found that the response of most potential producers of polysaccharides to tillage was site-specific, e.g., Oxalobacteraceae had higher potential to produce polysaccharides under reduced tillage at one site, and showed the opposite response at another site. However, the response of some potential producers of polysaccharides to tillage did not depend on site characteristics, but rather on their taxonomic affiliation, i.e., all members of Actinobacteria that responded to tillage intensity had higher potential for exopolysaccharide and lipopolysaccharide production specifically under reduced tillage. This could be especially crucial for aggregate stability, as polysaccharides produced by different taxa have different "gluing" efficiency. Overall, our data indicate that tillage intensity could affect aggregate stability by both influencing the absolute abundance of genes involved in the production of exopolysaccharides and lipopolysaccharides, as well as by inducing shifts in the community of potential polysaccharide producers. The effects of tillage intensity depend mostly on site-specific conditions

Reduced Tillage Corn Trial

Minimum tillage practices have significant potential to reduce expenses and the potential negative environmental effects caused by intensive tillage operations. Conventional tillage practices require heavy machinery to work and groom the soil surface in preparation for the planter. The immediate advantage of reduced tillage for the farm operator is less fuel expense, equipment, time, and labor required. It’s also clear that intensive tillage potentially increases nutrient and soil losses to our surface waterways. By turning the soil and burying surface residue, more soil particles are likely to detach from the soil surface and increase the potential for run off from agricultural fields. Reducing the amount and intensity of tillage can help build soil structure and reduce soil erosion

Theoretical analysis of the spatial variability in tillage forces for fatigue analysis of tillage machines

This paper presents a new theoretical model to describe the spatial variability in tillage forces for the purpose of fatigue analysis of tillage machines. The proposed model took into account both the variability in tillage system parameters (soil engineering properties, tool design parameters and operational conditions) and the cyclic effects of mechanical behavior of the soil during failure ahead of tillage tools on the spatial variability in tillage forces. The stress-based fatigue life approach was used to determine the life time of tillage machines, based on the fact that the applied stress on tillage machines is primarily within the elastic range of the material. Stress cycles with their mean values and amplitudes were determined by the rainflow algorithm. The damage friction caused by each cycle of stress was computed according to the Soderberg criterion and the total damage was calculated by the Miner's law. The proposed model was applied to determine the spatial variability in tillage forces on the shank of a chisel plough. The equivalent stress history resulted from these forces were calculated by means of a finite element model and the Von misses criterion. The histograms of mean stress and stress amplitude obtained by the rainflow algorithm showed significant dispersions. Although the equivalent stress is smaller than the yield stress of the material, the failure by fatigue will occur after a certain travel distance. The expected distance to failure was found to be df=0.825×106km. It is concluded that the spatial variability in tillage forces has significant effect on the life time of tillage machines and should be considered in the design analysis of tillage machines to predict the life time. Further investigations are required to correlate the results achieved by the proposed model with field tests and to validate the proposed assumptions to model the spatial variability in tillage force

Dryland maize yields and water use efficiency in response to tillage and nutrient management practices in China

Rainfed crop production in northern China is constrained by low and variable rainfall. This study explored the effects of tillage and nutrient management practices on maize (Zea mays L.) yield and water use efficiency (WUE), at Shouyang Dryland Farming Experimental Station in northern China during 2003-2008. The experiment was set-up using a split-plot design with 3 tillage methods as main treatments: conventional, reduced (till with crop residue incoperated in fall but no-till in spring), and no-till. Sub-treatments were 3 NP fertilizer rates: 105-46, 179-78 and 210-92 kg N and P ha. -1 Maize grain yields were greatly influenced by the amount of growing season rainfall, and by soil water contents at sowing. Mean grain yields over the 6-year period in response to tillage treatments were 5604, 5347 and 5185 kg ha, under reduced, no-till and conventional tillage, respectively. Mean WUE was 13.7, 13.6 and 12.6 kg ha mm under reduced, no-till, and conventional tillage, respectively. Mean soil water contents at sowing and at harvest were significantly influenced by tillage treatments. At harvest time, the no-till treatment had ~8-12% more water in the soil than the conventional and reduced tillage treatments. Under conventional tillage, grain yields increased with NP fertilizer application rates. However, under reduced tillage, grain yields were highest with lowest NP fertilizer application rate. In conclusion, grain yields and WUE were highest under reduced tillage at modest NP fertilizer application rates of 105 kg N and 46 kg P per ha. No-till increased soil water storage by 8-12% and improved WUE compared to conventional tillage

Minimum Tillage Corn Trial

Minimum tillage practices have significant potential to reduce expenses and the potential negative environmental effects caused by intensive tillage operations. Conventional tillage practices require heavy machinery to work and groom the soil surface in preparation for the planter. The immediate advantage of reduced tillage for the farm operator is less fuel expense, equipment, time, and labor required. It’s also clear that intensive tillage potentially increases nutrient and soil losses to our surface waterways. By turning the soil and burying surface residue, more soil particles are likely to detach from the soil surface and increase the potential for run off from agricultural fields. Reducing the amount and intensity of tillage can help build soil structure and reduce soil erosion

Adoption of Maize Conservation Tillage in Azuero, Panama

An aggressive research and validation program launched in 1984 in Azuero, Panama, yielded a recommendation advocating zero tillage for maize production. Ten years later, maize farmers in Azuero used three land preparation methods: conventional tillage, zero tillage, and minimum tillage (an adaptation of the zero tillage technology). This study aimed to quantify the adoption of zero and minimum tillage for maize in Azuero; identify factors influencing adoption of the different land preparation practices; and analyze the implications of the findings for future maize research and extension. Between 1985 and 1994, farmers in Region I of Azuero changed from conventional tillage to zero (33%) and minimum tillage (43%). In Regions II and III, most farmers still practiced conventional tillage in 1994, although 34% had switched to minimum tillage. Across regions, adoption of conservation tillage was motivated by potential cost savings rather than longer term considerations such as reduced soil erosion. The factors that limit adoption of conservation tillage vary by region. In Region I, adoption of conservation tillage is limited by land rental rather than ownership and by lack of conservation tillage planting equipment. In Regions II and III, lack of information about conservation tillage technology limits the probability of adoption. Future research should examine soil compaction, a key variable for understanding differences between the adoption of minimum and zero tillage. Another area that merits further research is the link between weeds and conservation tillage: several farmers reported using the technology to obtain better weed control. The long-term effects of conservation tillage should also be assessed. Extension in Regions II and III should seek to accelerate adoption of conservation tillage, particularly zero tillage. In Region I, extension should steer the change process from minimum to zero tillage.Crop Production/Industries,

Effect of tillage practices on the soil carbon dioxide flux during fall and spring seasons in a Mediterranean Vertisol

In this study, we assessed the effect of conventional tillage (CT), reduced (RT) and no tillage (NT) practices on the soil CO2 flux of a Mediterranean Vertisol in semi-arid Morocco. The measurements focused on the short term (0 to 96 h) soil CO2 fluxes measured directly after tillage during the fall and spring period. Soil temperature, moisture and soil strength were measured congruently to study their effect on the soil CO2 flux magnitude. Immediately after fall tillage, the CT showed the highest CO2 flux (4.9 g m-2 h-1); RT exhibited an intermediate value (2.1 g m-2 h-1) whereas the lowest flux (0.7 g m-2 h-1) was reported under NT. After spring tillage, similar but smaller impacts of the tillage practices on soil CO2 flux were reported with fluxes ranging from 1.8 g CO2 m-2 h-1 (CT) to less than 0.1 g CO2 m-2 h-1 (NT). Soil strength was significantly correlated with soil CO2 emission; whereas surface soil temperature and moisture were low correlated to the soil CO2 flux. The intensity of rainfall events before fall and spring tillage practices could explain the seasonal CO2 flux trends. The findings promote conservation tillage and more specifically no tillage practices to reduce CO2 losses within these Mediterranean agroecosystems. (Résumé d'auteur