The influence of organic matter on aggregate stability in some British soils

Chaney, Keith; Swift, R. S.

doi:10.1111/j.1365-2389.1984.tb00278.x

Cited by 381 publications

(168 citation statements)

References 19 publications

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“…There is a range of soil physical, chemical and biological consequences to declining SOM caused by tillage. A decline in SOM reduces soil particle aggregation (Chaney and Swift, 1984), which slows water infiltration (Thierfelder and Wall, 2010), reduces aeration and increases bulk density, thereby restricting root distribution and function. With reduced SOM, soil water holding capacity is decreased and susceptibility to water erosion increased through increased runoff (Thierfelder and Wall, 2010).…”

Section: Tillage Effects On Soil Qualitymentioning

confidence: 99%

Conservation agriculture for small holder rainfed farming: Opportunities and constraints of new mechanized seeding systems

Johansen¹,

Haque²,

Bell

et al. 2012

Field Crops Research

160

130

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Small holder farmers in rainfed agriculture believe that soil tillage is needed to maximize crop yields.However, as cropping intensity, and hence tillage intensity, increases there may be a decline in particular physical, chemical and biological properties of the soil which limit crop yield. This is primarily caused by declining soil organic matter, its oxidation being accelerated by tillage, particularly in warmer climates, and exacerbated by the limited return of above-ground biomass to the soil due to its competing use for other purposes. In large-scale commercial agriculture declining soil quality has been effectively addressed by conservation agriculture-cropping systems based on minimum tillage, crop residue retention and appropriate crop rotations and associations, preferably including legumes. This has required development of minimum tillage planting equipment along with herbicide technology to achieve weed control that is traditionally achieved through tillage. However, a shortage of mechanized options suitable for small holder farmers is creating an impediment to the adoption of conservation agriculture practices that would arrest the decline in soil quality in their fields. In South Asia, two-wheel tractors are replacing animal-drawn ploughing in small holder plots.This speeds the tillage operation and hence the turnaround time between crops, which may increase opportunities for crop intensification, but the problems associated with full tillage remain. Over the previous decade planter attachments to two-wheel tractors have been developed which permit seed and fertilizer placement with minimum to zero tillage in a single-pass. Recent tests have demonstrated that use of these implements can produce crop yields equal to or better than conventional tillage involving hand broadcasting of seed and fertilizer. Further, fuel and labour costs, seed and fertilizer inputs and turnaround time between crops can be reduced. In Africa, the introduction of animal-drawn rippers and direct seeders, originally developed for small-scale farmers in Brazil, is considered as a major breakthrough to small-scale farmer mechanization. It significantly reduces labour required for planting and benefits may be even greater if herbicides can be effectively used for weed control.Nevertheless, movement towards minimum tillage with two-wheel tractor mounted planters and animal-drawn direct seeding equipment is constrained by weed management issues. There are problems of availability and of safe and effective use of herbicides by resource-poor farmers and there is a need to develop more integrated weed management strategies that can be combined with smallscale planters. There is also a need to optimize the performance of small-scale planters to suit farmers' needs in different agro-ecological environments. Tools and concepts are now available to implement conservation agriculture for small holders and thereby increase profitability of their cropping practices and at the same time improve soil quality and sustainability of the...

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Section: Tillage Effects On Soil Qualitymentioning

confidence: 99%

Conservation agriculture for small holder rainfed farming: Opportunities and constraints of new mechanized seeding systems

Johansen¹,

Haque²,

Bell

et al. 2012

Field Crops Research

160

130

View full text Add to dashboard Cite

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“…In the SOM-poor sandy sites biochar application increased SOC by almost the same magnitude (38% increase) whereas manure and Tithonia increased SOC by a narrower margin (19% and 9%, respectively; data not shown) compared with the clayey sites. The soil texture influences SOC storage, stabilization, and aggregate stability (Chaney and Swift 1984;Schlecht-Pietsch and others 1994;Plante and others 2006) mainly through direct and indirect effects on the physical and chemical protection of soil organic matter (Plante and others 2006). Therefore, improved plant productivity observed with the high quality OM in the sandier sites compared with the clayey sites could be attributed to the high mineralization rate in the sandy sites resulting in immediate nutrient release for plant growth.…”

Section: Effects Of Soil Texture On Reversibility Of Productivity Decmentioning

confidence: 99%

Reversibility of Soil Productivity Decline with Organic Matter of Differing Quality Along a Degradation Gradient

et al. 2008

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In the highlands of Western Kenya, we investigated the reversibility of soil productivity decline with increasing length of continuous maize cultivation over 100 years (corresponding to decreasing soil organic carbon (SOC) and nutrient contents) using organic matter additions of differing quality and stability as a function of soil texture and inorganic nitrogen (N) additions. The ability of additions of labile organic matter (green and animal manure) to improve productivity primarily by enhanced nutrient availability was contrasted with the ability of stable organic matter (biochar and sawdust) to improve productivity by enhancing SOC. Maize productivity declined by 66% during the first 35 years of continuous cropping after forest clearing. Productivity remained at a low level of 3.0 t grain ha -1 across the chronosequence stretching up to 105 years of continuous cultivation despite full N-phosphorus (P)-potassium (K) fertilization (120-100-100 kg ha )1 ). Application of organic resources reversed the productivity decline by increasing yields by 57-167%, whereby responses to nutrient-rich green manure were 110% greater than those from nutrient-poor sawdust. Productivity at the most degraded sites (80-105 years since forest clearing) increased in response to green manure to a greater extent than the yields at the least degraded sites (5 years since forest clearing), both with full N-P-K fertilization. Biochar additions at the most degraded sites doubled maize yield (equaling responses to green manure additions in some instances) that were not fully explained by nutrient availability, suggesting improvement of factors other than plant nutrition. There was no detectable influence of texture (soils with either 11-14 or 45-49% clay) when low quality organic matter was applied (sawdust, biochar), whereas productivity was 8, 15, and 39% greater (P < 0.05) on sandier than heavier textured soils with high quality organic matter (green and animal manure) or only inorganic nutrient additions, respectively. Across the entire degradation range, organic matter additions decreased the need for additional inorganic fertilizer N irrespective of the quality of the organic matter. For low quality organic resources (biochar and sawdust), crop yields were increasingly responsive to inorganic N fertilization with increasing soil degradation. On the other hand, fertilizer N additions did not 726improve soil productivity when high quality organic inputs were applied. Even with the tested full N-P-K fertilization, adding organic matter to soil was required for restoring soil productivity and most effective in the most degraded sites through both nutrient delivery (with green manure) and improvement of SOC (with biochar).

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“…A matéria orgânica, funcionando como agente cimentante do solo, tem sido foco de vários trabalhos (Baver, 1968;Tisdall & Oades, 1982;Chaney & Swift, 1984;Silva & Mielniczuk, 1998;Castro Filho et al, 1998). O aumento da estabilidade dos agregados está intimamente relacionado com a capacidade da matéria orgânica de se aderir às partículas minerais do solo, formando as ligações argilo-metal-húmicas (Edwrds & Bremner, 1967).…”

Section: Introductionunclassified

Formação e estabilização de agregados do solo influenciados por ciclos de umedecimento e secagem após adição de compostos orgânicos com diferentes características hidrofóbicas

Bastos¹,

Mendonça

et al. 2005

Rev. Bras. Ciênc. Solo

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RESUMOA adição de compostos orgânicos e os ciclos de umedecimento e secagem do solo têm influência marcante na agregação do solo. Este trabalho objetivou estudar o efeito do tempo de incubação e a influência dos ciclos de umedecimento e secagem sobre a ação de compostos orgânicos com características hidrofóbicas e hidrofílicas na agregação de um Latossolo Vermelho-Amarelo distrófico. Os tratamentos dos experimentos de períodos de incubação e de ciclos de umedecimento e secagem seguiram esquema fatorial incompleto 2 x 3[(4-1) + (4-1)]. Os fatores foram: TFSA de dois horizontes (A e B), três períodos de incubação (40, 80 e 160 dias), três compostos orgânicos (amido, ácido esteárico e ácido húmico), em combinações de ausência e presença de amido e ácido húmico (Am e AH), (4-1) e de ácido esteárico e ácido húmico (E e AH), (4-1). Todas as unidades experimentais foram mantidas em incubadora de DBO a 25 o C e em ambiente natural, quando foram submetidas a 5, 11 e 22 ciclos de umedecimento e secagem, de acordo com os períodos de incubação. Após incubação, as amostras de agregados foram analisadas quanto ao diâmetro médio ponderado, diâmetro médio geométrico, índice de estabilidade de agregados e grau de repelência à água. Os resultados indicaram que a aplicação, mesmo em longos períodos de incubação, de compostos orgânicos com caráter hidrofóbico acentuado mostrou efeito marcante na melhoria da estabilidade em água do agregados, sendo sua melhor resposta na dose de 5,5 g kg -1 . Para melhorar a agregação, a aplicação

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The influence of organic matter on aggregate stability in some British soils

Cited by 381 publications

References 19 publications

Conservation agriculture for small holder rainfed farming: Opportunities and constraints of new mechanized seeding systems

Conservation agriculture for small holder rainfed farming: Opportunities and constraints of new mechanized seeding systems

Reversibility of Soil Productivity Decline with Organic Matter of Differing Quality Along a Degradation Gradient

Formação e estabilização de agregados do solo influenciados por ciclos de umedecimento e secagem após adição de compostos orgânicos com diferentes características hidrofóbicas

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