Three long-term field trials in humid regions of Canada and the USA were used to evaluate the influence of soil depth and sample numbers on soil organic carbon (SOC) sequestration in no-tillage (NT) and moldboard plow...Three long-term field trials in humid regions of Canada and the USA were used to evaluate the influence of soil depth and sample numbers on soil organic carbon (SOC) sequestration in no-tillage (NT) and moldboard plow (MP) corn (Zea mays L.) and soybean (Glycine max L.) production systems. The first trial was conducted on a Maryhill silt loam (Typic Hapludalf) at Elora, Ontario, Canada, the second on a Brookston clay loam (Typic Argiaquoll) at Woodslee, Ontario, Canada, and the third on a Thorp silt loam (Argiaquic Argialboll) at Urbana, Illinois, USA. No-tillage led to significantly higher SOC concentrations in the top 5 cm compared to MP at all 3 sites. However, NT resulted in significantly lower SOC in sub-surface soils as compared to MP at Woodslee (10-20 cm, P = 0.01) and Urbana (20-30 cm, P < 0.10). No-tillage had significantly more SOC storage than MP at the Elora site (3.3 Mg C ha-1) and at the Woodslee site (6.2 Mg C ha-1) on an equivalent mass basis (1350 Mg ha-1 soil equivalent mass). Similarly, NT had greater SOC storage than MP at the Urbana site (2.7 Mg C ha-1) on an equivalent mass basis of 675 Mg ha-1 soil. However, these differences disappeared when the entire plow layer was evaluated for both the Woodslee and Urbana sites as a result of the higher SOC concentrations in MP than in NT at depth. Using the minimum detectable difference technique, we observed that up to 1500 soil sample per tillage treatment comparison will have to be collected and analyzed for the Elora and Woodslee sites and over 40 soil samples per tillage treatment comparison for the Urbana to statistically separate significant differences in the SOC contents of sub-plow depth soils. Therefore, it is impracticable, and at the least prohibitively expensive, to detect tillage-induced differences in soil C beyond the plow layer in various soils.展开更多
Minimum tillage is a soil conservation practice involving a reduction in soil disturbance and topsoil compaction, which could minimize environmental impact of the tobacco cultivation system. The objectives of this stu...Minimum tillage is a soil conservation practice involving a reduction in soil disturbance and topsoil compaction, which could minimize environmental impact of the tobacco cultivation system. The objectives of this study were to evaluate the development and growth responses of Nicotiana tabacum and the changes in the physical and hydrological soil properties after the application of two different treatments: minimum tillage (MT) and conventional tillage (CT). MT did not cause any pronounced differences in the crop yield compared to CT, instead it positively affected the physical and hydrological soil properties and the plants’ vegetative growth. Under MT, the soil showed a higher structural stability than CT with significantly lower compaction values. With MT the soil showed a higher capacity to maintain and store water during the drought periods, evidenced by soil moisture values significantly higher than CT. Tobacco on MT showed a good response, significantly prolonging the vegetative growth stage which at harvest determined a higher stem height, greater number of leaves and longer internodes.展开更多
The objective of this research was to determine the capacity of a soil tillage system in soil conservation,in productivity and in energy efficiency.The minimum tillage and no-tillage systems represent good alternative...The objective of this research was to determine the capacity of a soil tillage system in soil conservation,in productivity and in energy efficiency.The minimum tillage and no-tillage systems represent good alternatives to the conventional(plough)system of soil tillage,due to their conservation effects on soil and to the good production of crops(Maize,96%-98%of conventional tillage for minimum tillage,and 99.8%of conventional tillage for no till;Soybeans,103%-112%of conventional tillage for minimum tillage and 117%of conventional tillage for no till;Wheat,93%-97%of conventional tillage for minimum tillage and 117%of conventional tillage for no till.The choice of the right soil tillage system for crops in rotation help reduce energy consumption,thus for maize:97%-98%energy consumption of conventional tillage when using minimum tillage and 91%when using no-tillage;for soybeans:98%energy consumption of conventional tillage when using minimum tillage and 93 when using no-tillage;for wheat:97%-98%energy consumption of conventional tillage when using minimum tillage and 92%when using no-tillage.Energy efficiency is in relation to reductions in energy use,but also might include the efficiency and impact of the tillage system on the cultivated plant.For all crops in rotation,energy efficiency(energy produced from 1 MJ consumed)was the best in no-tillage-10.44 MJ ha-1 for maize,6.49 MJ ha-1 for soybean,and 5.66 MJ ha-1 for wheat.An analysis of energy-efficiency in agricultural systems includes the energy consumed-energy produced-energy yield comparisons,but must be supplemented by soil energy efficiency,based on the conservative effect of the agricultural system.Only then will the agricultural system be sustainable,durable in agronomic,economic and ecological terms.The implementation of minimum and no-tillage soil systems has increased the organic matter content from 2%to 7.6%and water stable aggregate content from 5.6%to 9.6%,at 0-30 cm depth,as compared to the conventional system.Accumulated water supply was higher(with 12.4%-15%)for all minimum and no-tillage systems and increased bulk density values by 0.01%-0.03%(no significant difference)While the soil fertility and the wet aggregate stability have initially been low,the effect of conservation practices on the soil characteristics led to a positive impact on the water permeability in the soil.Availability of soil moisture during the crop growth period led to a better plant watering condition.Subsequent release of conserved soil water regulated the plant water condition and soil structure.展开更多
文摘Three long-term field trials in humid regions of Canada and the USA were used to evaluate the influence of soil depth and sample numbers on soil organic carbon (SOC) sequestration in no-tillage (NT) and moldboard plow (MP) corn (Zea mays L.) and soybean (Glycine max L.) production systems. The first trial was conducted on a Maryhill silt loam (Typic Hapludalf) at Elora, Ontario, Canada, the second on a Brookston clay loam (Typic Argiaquoll) at Woodslee, Ontario, Canada, and the third on a Thorp silt loam (Argiaquic Argialboll) at Urbana, Illinois, USA. No-tillage led to significantly higher SOC concentrations in the top 5 cm compared to MP at all 3 sites. However, NT resulted in significantly lower SOC in sub-surface soils as compared to MP at Woodslee (10-20 cm, P = 0.01) and Urbana (20-30 cm, P < 0.10). No-tillage had significantly more SOC storage than MP at the Elora site (3.3 Mg C ha-1) and at the Woodslee site (6.2 Mg C ha-1) on an equivalent mass basis (1350 Mg ha-1 soil equivalent mass). Similarly, NT had greater SOC storage than MP at the Urbana site (2.7 Mg C ha-1) on an equivalent mass basis of 675 Mg ha-1 soil. However, these differences disappeared when the entire plow layer was evaluated for both the Woodslee and Urbana sites as a result of the higher SOC concentrations in MP than in NT at depth. Using the minimum detectable difference technique, we observed that up to 1500 soil sample per tillage treatment comparison will have to be collected and analyzed for the Elora and Woodslee sites and over 40 soil samples per tillage treatment comparison for the Urbana to statistically separate significant differences in the SOC contents of sub-plow depth soils. Therefore, it is impracticable, and at the least prohibitively expensive, to detect tillage-induced differences in soil C beyond the plow layer in various soils.
文摘Minimum tillage is a soil conservation practice involving a reduction in soil disturbance and topsoil compaction, which could minimize environmental impact of the tobacco cultivation system. The objectives of this study were to evaluate the development and growth responses of Nicotiana tabacum and the changes in the physical and hydrological soil properties after the application of two different treatments: minimum tillage (MT) and conventional tillage (CT). MT did not cause any pronounced differences in the crop yield compared to CT, instead it positively affected the physical and hydrological soil properties and the plants’ vegetative growth. Under MT, the soil showed a higher structural stability than CT with significantly lower compaction values. With MT the soil showed a higher capacity to maintain and store water during the drought periods, evidenced by soil moisture values significantly higher than CT. Tobacco on MT showed a good response, significantly prolonging the vegetative growth stage which at harvest determined a higher stem height, greater number of leaves and longer internodes.
基金performed under the frame of the Partnership in priority domains-PNII,developed with the support of MEN-UEFISCDI,project no.PN-II-PT-PCCA-2013-4-0015:Expert System for Risk Monitoring in Agriculture and Adaptation of Conservative Agricultural Technologies to Climate Change.
文摘The objective of this research was to determine the capacity of a soil tillage system in soil conservation,in productivity and in energy efficiency.The minimum tillage and no-tillage systems represent good alternatives to the conventional(plough)system of soil tillage,due to their conservation effects on soil and to the good production of crops(Maize,96%-98%of conventional tillage for minimum tillage,and 99.8%of conventional tillage for no till;Soybeans,103%-112%of conventional tillage for minimum tillage and 117%of conventional tillage for no till;Wheat,93%-97%of conventional tillage for minimum tillage and 117%of conventional tillage for no till.The choice of the right soil tillage system for crops in rotation help reduce energy consumption,thus for maize:97%-98%energy consumption of conventional tillage when using minimum tillage and 91%when using no-tillage;for soybeans:98%energy consumption of conventional tillage when using minimum tillage and 93 when using no-tillage;for wheat:97%-98%energy consumption of conventional tillage when using minimum tillage and 92%when using no-tillage.Energy efficiency is in relation to reductions in energy use,but also might include the efficiency and impact of the tillage system on the cultivated plant.For all crops in rotation,energy efficiency(energy produced from 1 MJ consumed)was the best in no-tillage-10.44 MJ ha-1 for maize,6.49 MJ ha-1 for soybean,and 5.66 MJ ha-1 for wheat.An analysis of energy-efficiency in agricultural systems includes the energy consumed-energy produced-energy yield comparisons,but must be supplemented by soil energy efficiency,based on the conservative effect of the agricultural system.Only then will the agricultural system be sustainable,durable in agronomic,economic and ecological terms.The implementation of minimum and no-tillage soil systems has increased the organic matter content from 2%to 7.6%and water stable aggregate content from 5.6%to 9.6%,at 0-30 cm depth,as compared to the conventional system.Accumulated water supply was higher(with 12.4%-15%)for all minimum and no-tillage systems and increased bulk density values by 0.01%-0.03%(no significant difference)While the soil fertility and the wet aggregate stability have initially been low,the effect of conservation practices on the soil characteristics led to a positive impact on the water permeability in the soil.Availability of soil moisture during the crop growth period led to a better plant watering condition.Subsequent release of conserved soil water regulated the plant water condition and soil structure.
