1.IntroductionTillage has been an essential part ofinnovative development in the advancement of agribusiness, specifically inproduction.
The soil is tilled to achieve a fine tilth for the sowing of seed,water, and soil preservation, and weed control. Tillage exerts differentphysical, chemical and biological impacts on the soil both advantageous anddebasing, contingent upon the suitability of the systems utilized. The physicalimpacts, for example, aggregate stability, penetration rate, soil and waterpreservation, specifically, have a coordinate effect on soil profitability andmanageability. (FAO. 1993)However, as the world population growsat an alarming rate, food production has undergone a decline. This is in partdue to declining levels of soil productivity. Agriculture has to findinnovative ways of producing enough food to meet the demand, especially invulnerable regions like Africa and Asia, which are the most food insecure. Swilling and Annecke state that there ismounting evidence that the ecosystems that make agriculture possible aresteadily deteriorating as the levels of extraction and exploitation intensifies(Swilling & Annecke.
2012). Swilling and Annecke directly links decliningyield growth to soil degradation. To achieve food security we have to findsustainable ways of food production to meet the growing population demand. Tillage-based crop production systemsattributes to declining yields because of its effect on the soil and theenvironment. Moreover, the decline in yield growth attributes directly torising food prices making access to food harder. This paper aims to describethe root causes and the effects of environmental and economic problemsassociated with tillage-based crop production systems.
2.What is a tillage-based crop production system?Tillage is known as the mechanicalexploitation of the soil with the intention of growing crops. This disturbanceof the soil affects the soil characteristics such as soil water conservation,soil temperature, transpiration, and evapotranspiration processes.
This meansthat tillage exerts a footprint on the soil willfully to yield crops;therefore, damages the environment.Conventional tillage practice exerts themost impact on the soil. It is responsible for the loss of soil organic carboncontent, nitrate leaching, greenhouse emissions. Busari, Kukal, Bhatt &Duluzi claims that soil disturbance by conventional tillage makes the soilserve as a source rather than a sink of atmospheric pollutants and; thus, isunsustainable and environmentally friendly.Busari et al. list conservation tillagepractices as ranging from No-Till (NT), Reduced Tillage (RT), Mulch Tillage(MT), and Ridge Tillage to Contour Tillage. NT involves land cultivation withlittle or no soil disturbance, the only disturbance being during planting whileminimum tillage means a reduced level of manipulation involving plowing usingprimary tillage implements (Busari et al. ).
In mulch tillage, they state that thesoil is tilled in a manner that plant residues is left to cover the soilsurface to the highest degree. They explain ridge tilling as the planting ofcrops in rows along both sides or on top of the ridges prepared at thecommencement of the cropping season while contour tillage is when tillage is atright angles to the direction of the slope. 2.Soil properties (Hub, 2018) describes soil as comprisedof organic matter, mineral deposits, water, and air. The soil’s texture,structure, transpiration, and evapotranspiration is determined by thecombination of these elements. The texture has twoimportant physical properties when it comes to indicate the soil quality thoseare aggregate stability and size distribution.
The particle size distributionis the most essential physical property which defines the soil texture, andinfluences the soil properties the most. These two physical propertiesmentioned above reflects the resistance of soil erosion, especially inno-tillage system, which is why they are the most important factors when itcomes to soil quality. The soil structuredefines which different types of particles that are stored in the soil and itexert control over the physical, biological and chemical processes. It alsoexplains how and where the particles are located, which is important for howsuitable the soil is for growing crops. If the soil has a poorstructure, it can affect the nutrient availability and the nutrient uptake negativelyand increase the input energy requirement for tillage, increase the nutrientloss and the denitrification, which is negative from an environmental point ofview. Organic matter, tillage system, biological activity matters for theaggregate structure in a soil.Soil’s conductivity, which is theability of the soil particles to attract nutrients and is influenced by thepresence of organic matter in the soil. Nutrients are spared from leaching insoils with high organic matter content.
With less organic matter content andleaching of nutrients, overtime the soil can become more acidic. Various research has proven that tillagehas an impact on soils physical and chemical properties. To ensure soil wateravailabilty, nutrient availabilty, and proper root development, it must beensured there is very minimal disturbance to the soil.
3.Environmental effects of tillage Intensive tillage leads to soil erosion.Soil erosion is described as the detachment and movement of soil particles frompoint of origination through the action of water and wind. Wind erosion is themore visible, though water erosion is the most devastating. The loss of naturalnutrients and possible fertilizers directly affect crop emergence and growth.Seeds can be disturbed or removed and pesticides can be washed off.
This meansfewer nutrients for plants leading to reduced yields. Soil water erosion hasgreat environmental and economical implications as eroded soils can inhibit thegrowth of seeds, bury seedlings, contribute to road damage, and evencontaminate water sources.The topsoil typically has more organicmatter and more plant nutrients than the soil deeper in the soil profile.Associated with the organic matter are billions of soil micro-organisms.Micro-organisms are the engine that keeps a soil alive and productive. Numerousscientific studies have shown that soil with fewer micro-organisms or a lowerdiversity of micro-organisms is less productive than soils with a good balance.Erosion can be made more severe due to man’s influences. A soil with higherproportion of clay and humus usually increases the stability of structure andaggregates.
Aggregate stability is characterized by the sensitivity to externalinfluence. The essence of aggregate stability is the organic matter, becauselarge parts of plants and roots acts like a barrier and prevent aggregates tobreak into smaller units with help from decomposing of microorganisms thatprovides with an adhesive effect. With tillage systems, organic matter isgreatly reduced. Permeability is thesoil´s capacity to drain off water.
The structure of a soil is influenced inboth the long and short term of tillage and cultivation measures, which in turnaffects the soil physical properties. Tillageaffects soil quality, structure, stability, and texture, which in turn affectthe holding capacity of the soil referred to water infiltration rate. This isdue to the decrease in soil organic matter and the subsequent aggregatebreakdown. Tillage cause air to enter the soilparticles. When soil is more aerated, nitrous oxide escapes into the atmosphereoffsetting the cooling effect of carbon dioxide draw down.
N2O is the mostimportant agent for stratospheric ozone destruction. Soil is the largest sourceon N2O emissions and it is exasperated by tillage and the ever increasing useof synthetic nitrogen (N). (growingnations.co.za,2018) describes soil is one of the most important natural resources farmershave. In the absence of soil, farmers cannot farm.
As with other importantresources, it is vital to be protected or improved for the benefit andsustainability of future generations. Once soil leaves a farmers field it islost forever. As soil erodes from farmer’s fields, the most valuable part ofthe soil (the topsoil) is gone. 4.Economical effects of conventional tillageTillage operations are generally conducted toprepare a seedbed, incorporate fertilizers, and cultivate for weed control. Thenumber of trips required to perform these operations depends on soil type andcondition, the crop, weather conditions, and the type of tillage systemutilized. Excessive tillage operations increase fuel consumption, operatingcosts, machinery wear, and time and labor requirements.
Yield reductionreported for conventional reduced tillage systems due to poor soil quality.This has a domino effect on farm income, exports, and food security concerns. 5.ConclusionArable land suppliesfood and it is therefore important to develop the production and land-use plan ina sustainable way. To grow crops for food should be both economical andenvironmentally sustainable and the soil structure and quality should be takenin consideration when cultivating our land.
We need to find newapproaches to maintain good soil structure, and minimized tillage systems havemany advantages, including reduced costs for the growing of crops, whileleaving plant material in the fields can reduce erosion and increase thebiological activity and humus content of the soil.A non-cultivated soilgenerally has a better structure due to the higher content of organic matterand less compaction than a cultivated soil has. Soil structure is influenced bysoil and crop management inputs and has an impact on soil quality. One of thefactors that influence the quality is tillage. This input is an importantfactor and relevant in the point of sustainability Vegetation andrecycling of organic matter contributes to a better structure and physicalenvironment. Soil cultivation measures do the opposite. If the structure shouldbe improved, the structure-building measures needs to be greater than thestructure depleting measures such a conventional tillage systems.
Adding organic mattercan preserve soil structure and increase the crop safety. Measures to improvethe structure and provide better conditions for the crops, is to return cropresidues to the soil, grow cover crops and only apply shallow tillage or notill, which could increase the humus content in the top layer. Increased humuscontent will give a lower bulk density, increased aggregate stability andincreased porosity, which in turn give the soil increased water holdingcapacity and infiltration capacity. 6. Reference List Thierfelder, C.,Rusinamhodzi, L.
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