• Authors:
    • Martiniello, P.
  • Source: Agricultural Sciences
  • Volume: 3
  • Issue: 1
  • Year: 2012
  • Summary: Agricultural systems based on crop rotations favour sustainability of cultivation and productivity of the crops. Wheat-forage crops rotations (annual winter binary mixture and perennial alfalfa meadow) combined with irrigation are the agronomical techniques able to better exploit the weather resources in Mediterranean environments. The experiment aimed to study the effect of 18 years of combined effect of irrigation and continuous durum wheat and wheat-forage rotations on productivities of crops and organic matter of topsoil. The experiments were established through 1991-2008 under rainfed and irrigated treatments and emphasized on the effect of irrigation and continuous wheat and wheat-forage crop rotations on water use efficiency and sustainability of organic matter. The effect of irrigation increased 49.1% and 66.9% the dry matter of mixture and meadow, respectively. Continuous wheat rotation reduced seed yield, stability of production, crude protein characteristics of kernel and soil organic matter. The yearly gain in wheat after forage crops was 0.04 t (ha yr) 1 under rainfed and 0.07 t (ha yr) -1 under irrigation treatments. The crude protein and soil organic matter of wheat rotations, compared to those of continuous wheat under rainfed and irrigated was increase in term of point percentage by 0.8 and 0.5 in crude protein and 5.1 and 4.4 in organic matter, respectively. The rotations of mixture and meadow under both irrigated treatments increased the point of percentage of organic matter over continuous wheat (9.3.and 8.5 in mixture and 12.5 and 9.5 meadow under rainfed and irrigation, respectively). Irrigation reduce the impact of weather on crop growing reducing water use efficiency (mean over rotations) for dry matter production (15.5 in meadow and 17.5 in mixture [L water (kg dry matter) -1]) and wheat seed yield. The effect of agronomic advantages achieved by forage crops in topsoil expire its effect after three years of continuous wheat rotation.
  • Authors:
    • Mehta, V. M.
    • Rosenberg, N. J.
    • Mendoza, K.
  • Source: Agricultural and Forest Meteorology
  • Volume: 152
  • Issue: 1
  • Year: 2012
  • Summary: The Missouri River Basin (MRB) is the largest river basin in the U.S. and is one of the most important crop and livestock-producing regions in the world. In a previous study of associations between decadal climate variability (DCV) phenomena and hydro-meteorological (HM) variability in the MRB for the March-August period, and their impacts on stream flow in the MRB, it was found that positive and negative phases of the Pacific Decadal Oscillation (PDO), the tropical Atlantic sea-surface temperature gradient variability (TAG), and the west Pacific Warm Pool (WPWP) temperature variability were significantly associated with decadal variability in precipitation and surface air temperature in the MRB, with combinations of various phases of these DCV phenomena associated with dry, wet, or neutral HM conditions. It was also found that these DCV phenomena impact stream flow in the MRB substantially via their association with MRB hydro-meteorology. In the present study, the Erosion Productivity Impact Calculator model, also known as the Environmental Policy Integrated Climate (EPIC) model, calibrated and validated for the MRB, was used to simulate yields of dryland corn ( Zea mays L.) and spring and winter wheat ( Triticum aestivum L.), in response to HM anomalies associated with the three DCV phenomena. Realistic values of indices of the three DCV phenomena have major impacts on crop yields, as much as 40-50% of average yield in some locations in the MRB and also evident in MRB-aggregated crop yields; however, our results show that the impacts can be location-specific. Since each of the three DCV phenomena can persist in one phase or another for several years to a decade or longer, and since the simultaneous correlation among these phenomena is negligibly small, their combined and cumulative positive/negative effects on the MRB HM and agricultural production can be dramatic in this major American and global "bread basket". In addition, EPIC's success in simulating long-term crop yields in the MRB, taking technology trends into account, suggests that, if the evolution of major DCV phenomena can be forecast, it may be possible to forecast, as well, some multiyear to decadal measure of crop yields in the MRB with some skill.
  • Authors:
    • Anderson, R. L.
    • Liebig, M. A.
    • Krupinsky, J. M.
    • Hanson, J. D.
    • Tanaka, D. L.
    • Merrill, S. D.
  • Source: Agricultural Systems
  • Volume: 107
  • Year: 2012
  • Summary: The dynamic cropping systems concept proposes a long-term strategy of crop sequencing to achieve production, economic and soil care goals through sound ecological management. This requires that agriculturalists have comprehensive information about how crop species affect following years' crops. Little research exists about how differences in soil type and properties change crop sequence effects. Sandy loam, alluvial-derived soil in south central North Dakota, USA (400 mm/yr precipitation) was the site of a crop sequence experiment in which four species - maize ( Zea mays L.), dry pea ( Pisum sativum L.), spring wheat ( Triticum aestivum L.), and soybean ( Glycine max (L.) Merr.) - were grown in strips one year and in perpendicular strips the following, with spring wheat planted a third year. No-till management was used with three replications in land and two in time. Results were compared with those from two 10*10 sequence experiments on silt loam, glacial till-derived soil. Soil water depletion (SWD) and root growth were deeper in sandy loam soil than in silt loam. During a year of above average precipitation, prior year soybean enhanced spring wheat yield on sandy loam soil by 14% above average, but prior year spring wheat reduced it by 14%. During a year of deficient precipitation, prior crop effects on spring wheat yield ranked in order of expected springtime soil water storage: dry pea, 11%; spring wheat, 4%; soybean, -5%; maize, -10%. Prior crops' SWD largely determined spring soil water, with maize having greatest depletion. Excluding results from a year of low precipitation, prior crops' effects on spring wheat yield on sandy loam soil were similar to results found at two sequence experiments on silt loam soil: dry pea - generally positive effect (N-production, water conservation); spring wheat - negative (disease); soybean - positive (N-production); maize - generally negative (heavier water use). Same year comparison of three crops (nine sequences) on sandy loam soil vs. silt loam showed average dry pea and spring wheat yields being equivalent ( P<0.10). However, average maize yield was 37% lower on silt loam, with maize-after-maize yielding 54% less. The site with sandy loam land had topsoil with lower soil quality indicators (organic C, water holding capacity) than silt loam. However, no-till management and previous grass rendered productivity of the soils equivalent, and superior capacity of the sandy loam site subsoil to conduct water and be conducive to root growth lessened negative, water-generated crop sequence effects.
  • Authors:
    • Mukhwana, E. J.
    • Norton, U.
    • Norton, J. B.
  • Source: Soil Science Society of America Journal
  • Volume: 76
  • Issue: 2
  • Year: 2012
  • Summary: Soils typically show 20 to 40% decline in soil organic carbon (SOC) due to cultivation, most of it in the first 10 yr, but studies on SOC depletion may actually underestimate losses of the original SOC. Starting 40 to 50 yr ago, expanding use of non-inversion tillage, fertilizers, and herbicides lead to reduced disturbance and increased residue production that undoubtedly began recovery of SOC depleted during previous decades when farmers used only intensive tillage to control weeds and stimulate release of nutrients from crop residues. We measured SOC and total N stocks, density fractions, and labile C and N at 10 study sites in two rain-fed production areas in southeastern Wyoming. Systems evaluated include historic inversion-tillage-based winter wheat ( Triticum aestivum L.)-fallow with no inputs, conventional winter wheat-fallow, minimum- and no-till continuous rotations and permanent grass cover. Results were then compared to SOC under nearby native grasslands. Soils beneath historic wheat-fallow were the most depleted in SOC, with 13.8 and 17.6 Mg C ha -1 in the upper 30 cm at the two study areas, or 37% of the SOC under the two native sites. Soil OC contents were statistically similar across conventional, minimum-till, and no-till systems, ranging from 64 to 78% of native SOC levels, and significantly higher under permanent grass, with both sites having 90% of native SOC levels. Free light fraction organic carbon (LFOC) contents were lowest beneath the historic system, but increased in systems with fewer disturbances. When normalized by SOC and total N, the labile C and N pools generally increased with increasing disturbance, especially microbial biomass carbon (MBC) and dissolved organic carbon (DOC). Soil OC contents under the historic, inversion tillage system were much lower relative to native grasslands than found in other studies, which, together with other findings, suggest that SOC levels have begun to recover under the modern conventional system. Free LFOC and labile pool C and N contents indicate that conservation tillage systems in place for a relatively short time are facilitating further recovery of SOC.
  • Authors:
    • Moriasi, D.
    • Steiner, J. L.
    • Starks, P. J.
    • Saleh, A.
    • Osei, E.
  • Source: Journal of Soil and Water Conservation
  • Volume: 67
  • Issue: 2
  • Year: 2012
  • Summary: No-till farming has been identified as an important conservation practice with potential to improve soil quality and protect water quality. However, adoption of new tillage and production practices is determined by numerous economic and noneconomic factors in addition to land stewardship. The objective of this study was to assess the effects of fuel costs and crop yield on farm-level economics in no-till systems in comparison with other tillage systems for wheat production in southwestern Oklahoma. The Farm-level Economic Model, an annual economic simulation model, was used in conjunction with survey data from the Fort Cobb Reservoir Watershed in southwestern Oklahoma to determine impacts of alternative tillage practices on farm profits. Sensitivity analysis was performed using plausible ranges in diesel prices, winter wheat grain yields, herbicide costs, labor wages, and farm size. The results indicate that if winter wheat grain yields are not significantly impacted by tillage systems, no-till would be more profitable than conventional tillage or the current mix of tillage practices in the watershed. Only when there is a significant wheat yield penalty associated with no-till (10% or greater) might no-till be less profitable than conventional tillage or the status quo at reasonably high fuel prices. In general, for each 1% improvement in wheat yields under no-till relative to conventional tillage, no-till farm profits improve by US$7 ha -1 (US$3 ac -1) on farms that produce only winter wheat and an average of US$2.50 ha -1 (US$1 ac -1) if averaged across all farms in the Fort Cobb Reservoir Watershed, including those that do not produce winter wheat. The study also finds that higher diesel prices, higher labor wages, lower herbicide costs, and smaller farm sizes are all relatively advantageous to no-till.
  • Authors:
    • Singh, U. P.
    • Punia, M.
    • Gupta, R.
    • Sidhu, B. S.
    • Chandna, P.
    • Ladha, J. K.
  • Source: Applied Geography
  • Volume: 32
  • Issue: 2
  • Year: 2012
  • Summary: Satisfying the food demands of an ever-increasing population, preserving the natural resource base, and improving livelihoods are major challenges for South Asia. A large area of land in the Middle and Lower Gangetic Plains of South Asia remains either uncultivated or underused following the rice harvest in the kharif (wet) season. The area includes "rice-fallow," estimated at 6.7 million ha, flood-prone riversides (" diara lands," 2.4 million ha), waterlogged areas (4.9 million ha), and salt-affected soils (2.3 million ha). Bringing these lands under production could substantially improve the food supply and enhance livelihoods in the region. This paper describes a methodological case study that targeted resource-conserving technologies in underused lands of the Ballia District of eastern Uttar Pradesh (India) using multispectral remote-sensing images. Classification of temporal satellite data IRS-P6 in combination with Spot VGT 2 permitted the identification of all major categories of underused land during the post-rainy rabi/winter season, with an average accuracy of 89%. Based on three-year averages of field demonstrations, farmers gained an additional income of $63 ha -1 by introducing raised beds in salt-affected soils; $140 and $800 ha -1 by introducing deepwater rice varieties (monsoon) and boro rice (winter) in waterlogged areas; and $581 ha -1 by introducing zero-till lentil (winter) in rain-fed fallow lowland. Timely wheat planting through zero-tillage implies an additional income of $147 ha -1 and could increase wheat production by 35,000-65,000 tons in the district. The methodologies and technologies suggested in the study are applicable to more than 15 million ha of underutilized lands of the Indo-Gangetic Plains of South Asia. If the technologies are precisely applied, they can result in more than 3000 million US $ of additional income every year to these poverty prone areas.
  • Authors:
    • He, J.
    • Wang, Q.
    • Rasaily, R. G.
    • Li, H.
    • Lu, C.
  • Source: African Journal of Biotechnology
  • Volume: 11
  • Issue: 4
  • Year: 2012
  • Summary: An experiment was conducted to determine the effects of tillage on soil properties in the field of maize ( Zea mays L.) and winter wheat ( Triticum aestivum L.) annual double cropping region in North China Plain. Measurements were made following six years (2005 to 2010) of three tillage treatments; no till with controlled traffic (NTCT), no till random trafficking (NTRT) and conventional tillage (CT) on a silt loam according to the USDA texture classification system soil in Daxing district, which lies in the suburb of Beijing. Long term no till with controlled traffic significantly (P<0.05) increased macro-aggregates, infiltration rate, soil moisture, together with reductions in soil bulk density, soil compaction in different layers compared with the no till random traffic and traditional mould board tillage treatment currently used in this region. Consequently, mean winter wheat and summer maize yields for the NTCT treatment were improved by 2.8 and 7.1% when compared with the soils under no till random traffic, while huge improvement was found when it was compared with conventional ploughing management (4.2 and 12.08% for wheat and maize, respectively). The long-term experiment demonstrated that no-tillage controlled traffic with residues retained, offers a potentially significant improvement over the current farming systems in annual double cropping areas of North China Plain.
  • Authors:
    • Seufert, V.
    • Ramankutty, N.
    • Foley, J. A.
  • Source: Nature
  • Volume: 485
  • Issue: 7397
  • Year: 2012
  • Summary: Numerous reports have emphasized the need for major changes in the global food system: agriculture must meet the twin challenge of feeding a growing population, with rising demand for meat and high-calorie diets, while simultaneously minimizing its global environmental impacts. Organic farming - a system aimed at producing food with minimal harm to ecosystems, animals or humans - is often proposed as a solution. However, critics argue that organic agriculture may have lower yields and would therefore need more land to produce the same amount of food as conventional farms, resulting in more widespread deforestation and biodiversity loss, and thus undermining the environmental benefits of organic practices. Here we use a comprehensive meta-analysis to examine the relative yield performance of organic and conventional farming systems globally. Our analysis of available data shows that, overall, organic yields are typically lower than conventional yields. But these yield differences are highly contextual, depending on system and site characteristics, and range from 5% lower organic yields (rain-fed legumes and perennials on weak-acidic to weak-alkaline soils), 13% lower yields (when best organic practices are used), to 34% lower yields (when the conventional and organic systems are most comparable). Under certain conditions - that is, with good management practices, particular crop types and growing conditions - organic systems can thus nearly match conventional yields, whereas under others it at present cannot. To establish organic agriculture as an important tool in sustainable food production, the factors limiting organic yields need to be more fully understood, alongside assessments of the many social, environmental and economic benefits of organic farming systems.
  • Authors:
    • Robertson, G.
    • Tausig, J.
    • Hamilton, S.
    • Basso, B.
    • Syswerda, S.
  • Source: Agricultural Ecosystems and Environment
  • Volume: 149
  • Year: 2012
  • Summary: Nitrate (NO 3-) loss from intensively farmed cropland is a long-standing, recalcitrant environmental problem that contributes to surface and groundwater pollution and coastal zone hypoxia. Here nitrate leaching losses are reported from nine replicated cropped and unmanaged ecosystems in southwest Michigan, USA. Ecosystems include four annual corn-soybean-winter wheat rotations under conventional, no-till, reduced-input, and organic/biologically-based management, two perennial cropping systems that include alfalfa and hybrid poplar trees, and three unmanaged successional communities including an early successional community analogous to a cellulosic biofuel system as well as a mature deciduous forest. The organic, alfalfa, and unmanaged systems received no synthetic, manure, or compost nitrogen. Measured nitrate concentrations were combined with modeled soil water drainage to provide estimates of nitrate lost by leaching over 11 years. Among annual crops, average nitrate losses differed significantly ( pno-till (41.33.0)>reduced-input (24.30.7) > organic (19.00.8) management. Among perennial and unmanaged ecosystems, nitrate loss followed the pattern alfalfa (12.81.8 kg N ha -1 yr -1)=deciduous forest (11.04.2) >> early successional (1.10.4)=mid-successional (0.90.4) > poplar (<0.010.007 kg N ha -1 yr -1) systems. Findings suggest that nitrate loss in annual row crops could be significantly mitigated by the adoption of no-till, cover crops, and greater reliance on biologically based inputs, and in biofuel systems by the production of cellulosic rather than grain-based feedstocks.
  • Authors:
    • Ugarte, D. G. de la T.
    • English, B. C.
    • Roberts, R. K.
    • Larson, J. A.
    • Toliver, D. K.
    • West, T. O.
  • Source: Agronomy Journal
  • Volume: 104
  • Issue: 2
  • Year: 2012
  • Summary: This research evaluated differences in yields and associated downside risk from using no-till and tillage practices. Yields from 442 paired tillage experiments across the United States were evaluated with respect to six crops and environmental factors including geographic location, annual precipitation, soil texture, and time since conversion from tillage to no-till. Results indicated that mean yields for sorghum [ Sorghum bicolor (L.) Moench] and wheat ( Triticum aestivum L.) with no-till were greater than with tillage. In addition, no-till tended to produce similar or greater mean yields than tillage for crops grown on loamy soils in the Southern Seaboard and Mississippi Portal regions. A warmer and more humid climate and warmer soils in these regions relative to the Heartland, Basin and Range, and Fruitful Rim regions appear to favor no-till on loamy soils. With the exception of corn ( Zea mays L.) and cotton ( Gossypium hirsutum L.) in the Southern Seaboard region, no-till performed poorly on sandy soils. Crops grown in the Southern Seaboard were less likely to have lower no-till yields than tillage yields on loamy soils and thus had lower downside yield risk than other farm resource regions. Consistent with mean yield results, soybean [ Glycine max (L.) Merr.] and wheat grown on sandy soils in the Southern Seaboard region using no-till had larger downside yield risks than when produced with no-till on loamy soils. The key findings of this study support the hypothesis that soil and climate factors impact no-till yields relative to tillage yields and may be an important factor influencing risk and expected return and the adoption of the practice by farmers.