• Authors:
    • Anderson, R. L.
  • Source: Weed Technology
  • Volume: 23
  • Issue: 3
  • Year: 2009
  • Summary: This study measured weed interference in soybean and corn as affected by residue management tactics following a sequence of oat and winter wheat. Residue management tactics compared were conventional tillage, no-till, and no-till plus cover crops. Treatments were split into weed-free and weed-infested conditions; prominent weeds were green and yellow foxtail and common lambsquarters. Grain yield of soybean did not differ between weed-free and weed-infested conditions with no-till, whereas weeds reduced yield 25% in the tilled system. Corn responded inconsistently to treatments, with more than 40% yield loss due to weed interference in 1 yr with all treatments. Cover crops did not improve weed management compared with no-till in either crop. Seedling emergence of the weed community differed between tillage and no-till; density of weed seedlings was fivefold higher with tillage, whereas seedling emergence was delayed in no-till. The initial flush of seedlings occurred 2 to 3 wk later in no-till compared with the tilled system. Designing rotations to include cool-season crops in a no-till system may eliminate the need for herbicides in soybean to manage weeds.
  • Authors:
    • Smith, H. J.
    • Trytsman, G.
    • Bloem, J. F.
  • Source: Biological Nitrogen Fixation: Towards Poverty Alleviation through Sustainable Agriculture
  • Volume: 48
  • Issue: 1-3
  • Year: 2009
  • Summary: Farm lands of resource-poor communities in South Africa are depleted of nutrients due to continuous mono-cropping, limited use of fertilisers, and sometimes leaching caused by high rainfall. Despite the well-known advantages of biological nitrogen fixation (BNF) in cropping systems, less than 10% of the grain crops planted annually in these areas are legumes. Using a participatory research and development approach, resource-poor farmers were introduced to conservation agriculture (CA) practices, including BNF, that promoted zero (or reduced) tillage, increased retention of soil cover, as well as crop diversification. Because crop rotation and intercropping of legumes with cereals are known to contribute to soil fertility while enhancing food security, resource-poor fanners from various Provinces in South Africa were trained on the benefits of legume culture for eight years. As a result, these resource-poor farmers did not only get training in inoculation techniques, but were also supplied with inoculants for use on their farms. Data collected from Farmers Demonstration Trials at Belvedere, Dumbarton and Lusikisiki, showed that the grain and fodder yield of maize planted after legumes, and maize intercropped with legumes, were comparable to those of maize receiving high N fertilizer dose (i.e. 54 kg N at planting and 54 kg N as top-dressing). The same data further showed that Rhizobium inoculation, when combined with application of low levels of P and K. significantly increased crop yields within farmers' trial plots. BNF therefore offers a great opportunity for resource-poor farmers in South Africa to increase their crop yields and thus improve the quality of their livelihoods through the adoption of affordable and sustainable biological technologies that enhance soil fertility.
  • Authors:
    • Jabro, J. D.
    • Sainju, U.
    • Stevens, W. B.
    • Evans, R. G.
  • Source: Journal of Environmental Management
  • Volume: 88
  • Issue: 4
  • Year: 2008
  • Summary: Among greenhouse gases, carbon dioxide (CO 2) is one of the most significant contributors to regional and global warming as well as climatic change. A field study was conducted to (i) determine the effect of soil characteristics resulting from changes in soil management practices on CO 2 flux from the soil surface to the atmosphere in transitional land from perennial forages to annual crops, and (ii) develop empirical relationships that predict CO 2 flux from soil temperature and soil water content. The CO 2 flux, soil temperature ( Ts), volumetric soil water content (theta v) were measured every 1-2 weeks in no-till (NT) and conventional till (CT) malt barley and undisturbed soil grass-alfalfa (UGA) systems in a Lihen sandy loam soil (sandy, mixed, frigid Entic Haplustoll) under irrigated and non-irrigated conditions in western North Dakota. Soil air-filled porosity (epsilon) was calculated from total soil porosity and theta v measurements. Significant differences in CO 2 fluxes between land management practices (irrigation and tillage) were observed on some measurement dates. Higher CO 2 fluxes were detected in CT plots than in NT and UGA treatments immediately after rainfall or irrigation. Soil CO 2 fluxes increased with increasing soil moisture ( R2=0.15, P<0.01) while an exponential relationship was found between CO 2 emission and Ts ( R2=0.59). Using a stepwise regression analysis procedure, a significant multiple regression equation was developed between CO 2 flux and theta v, Ts (CO 2 flux=e -3.477+0.123T s+6.381theta v ; R2=0.68, P≤0.01). Not surprisingly, soil temperature was a driving factor in the equation, which accounted for approximately 59% in variation of CO 2 flux. It was concluded that less intensive tillage, such as no-till or strip tillage, along with careful irrigation management will reduce soil CO 2 evolution from land being converted from perennial forages to annual crops.
  • Authors:
    • Gathala, M. K.
    • Singh, K. K.
    • Sharma, S. K.
    • Saharawat, Y. S.
    • Tetarwal, J. P.
    • Ladha ,J. K.
    • Gupta, R. K.
    • Jat, M. L.
    • Singh, S.
  • Source: ACIAR PROCEEDINGS
  • Issue: 127
  • Year: 2008
  • Summary: Resource-conserving technologies with double no-till practices represent a major shift in production techniques for attaining optimal productivity, profitability and water use in rice-wheat (RW) systems in the Indo-Gangetic Plain. Permanent raised beds (PRB) and double no-till with flat layouts are under evaluation for RW systems for a range of soils, climate, cultivars and seeding/crop establishment techniques (dry seeding, transplanting). To date, results have been inconsistent and systematic information on trials with PRB is lacking. Four researcher- and farmer-managed experiments were conducted with various tillage and crop establishment techniques for RW on PRB and flat layouts. The yield of rice on PRB was significantly lower than that on double no-till flat layouts, whereas wheat yield was highest on PRB. The total RW system yield with PRB was similar to that of other tillage and crop establishment techniques. However, irrigation and input (irrigation plus rain) water productivity (kg grain/m 3 of water) of both rice and wheat was much higher on PRB. In farmer-managed trials of transplanted basmati rice on PRB, profitability was highest on PRB (US$684/ha) and lowest with traditional practices (US$531/ha). In a researcher-managed long-term experiment, the soil physical properties (bulk density, mean weight diameter of aggregates, cone index and infiltration rate) improved significantly on PRB compared with the conventional puddled transplanted rice-tilled wheat system.
  • Authors:
    • Jia, H.
    • Chen, Z.
    • Ma, C.
    • Yang, Q.
    • Liu, Z.
    • Li, G.
  • Source: Nongye Jixie Xuebao = Transactions of the Chinese Society for Agricultural Machinery
  • Volume: 39
  • Issue: 11
  • Year: 2008
  • Summary: This paper describes the tillage technologies for the tillage system of soil water storage and preservation in the area of dry farming of northern China, with surface mulching, reduced-till and no-till as the core technologies, based on combined operations, to achieve the goal of soil water storage and preservation and improving soil fertility. It summarizes six innovative technologies involving the combined stalk and stubble management technology, in which the stalk and stubble of corn can be broken and partially buried in soil at one time; the universal technology for rototilling and stubble breaking, in which the two operations, can be done on the same blade rotor and disc; the strip reduced-till (no-till) precision seeding technology, in which less-tillage (or only furrowing) is needed in the seed bed; the ridging and film-side furrow sowing technology, in which the ridge is covered with the film and seeds are sowed in the furrow; the mechanical bionic resistance reduction technology, which uses the soil working tool designed based on bionics; and the no-till planting and blockage prevention technology, in which no-till planting is conducted in the residue free seed bed. It also shows the composition diagram of the farming system.
  • Authors:
    • Wang, Z.
    • Hao, M.
    • Wang, L.
    • Li, S.
    • Li, X.
  • Source: Scientia Agricultura Sinica
  • Volume: 41
  • Issue: 9
  • Year: 2008
  • Summary: Objective: Research on effects of monocropping or rotation of different crops on water and different forms of soil organic nitrogen (N) and mineral N in dryland soils is recognized to be of great significance in determining dryland crop sequences, increasing soil fertility, and optimizing nutrients management. Method: Dryland soil samples were taken from 6 cropping systems: fallowing, continuous wheat monocropping, continuous maize monocropping, continuous alfalfa cropping with no-till, pea-wheat-wheat-millet rotation and maize-wheat-wheat-millet rotation, from a 23-year long-term experimental site on the Loess Plateau, to study the effects of cropping systems on soil water, organic N, light fraction organic N and mineral N. Result: Results obtained showed that continuous long-term fallowing system contained the lowest organic N, light fraction organic N and mineral N. Long-period alfalfa cropping with no-till system could promote water storage in topsoil layers, and accumulation of organic and light fraction organic N in 0-20 cm soil layers, but increased exhaustion of water and mineral N in deep soil layers. Continuous monocropping of wheat or maize could all significantly increase soil organic and light fraction organic N contents, and the organic N were increased more by monocropping of wheat. Organic N contents in soil layers of two rotation systems showed no obvious different to monocropping of wheat. Light fraction organic N contents also were not obvious different between two rotations in 0-20 cm soil layers, but they were all significantly higher than wheat or maize monocropping. The amount of soil mineral N was found to depend on the status of crop growing or N fertilizer application at sampling time. Conclusion: Although long term monocropping of legumes without tillage can enhance organic N accumulation by increase the light fraction organic N in soil, the exhaustion of soil water in deep layers is also increased. Rotations of legumes with cereal crops or the shallow and deep root crop rotations are proved to be feasible measures to optimize soil water utilization, increase organic N accumulation in soil, and synergize soil N supply capacity.
  • Authors:
    • Munir, A.
    • Ramzan, M.
    • Mann, R. A.
  • Source: International Journal of Agriculture & Biology
  • Volume: 10
  • Issue: 3
  • Year: 2008
  • Summary: Wheat and rice are the major food staples around the globe including Pakistan. The challenge of increasing food production in the next 20 years to match population growth is daunting and warrants improvement in the quality of natural resources for growing more food from marginal and degraded lands. Cost of cultivation must be reduced and at the same time, efficiency of resources like irrigation water, fuel, fertilizers must be improved to make the crop production system more viable and eco-friendly. Resource Conserving Technology (RCT) must figure highly in this equation since it plays a crucial role in achieving the above goals. The RCTs include laser land leveling, zero-tillage, bed furrow irrigation method and crop residue management. These technologies were evaluated in irrigated areas of Punjab province where rice follows wheat. Water use efficiency was increased by 20% in laser leveled fields. Zero-tillage technology resulted in a significant saving of irrigation water (22%), fuel (78%), cultivation (88%) and herbicide use (33%) compared to conventional, thus increasing yields and farmer's profits. Soil properties and microbial population including bacteria, fungi and actinomyces improved in the zero-till fields. Planting of wheat on raised beds is making headway in low-lying and poorly drained areas. Thus, resource conservation tillage technology provides a tool for making progress towards improving and sustaining wheat production, helping with food security and poverty alleviation in Pakistan in the next few decades.
  • Authors:
    • Reddy, K. C.
    • Reddy, S. S.
    • Nyakatawa, E. Z.
    • Raper, R. L.
    • Reeves, D. W.
    • Lemunyon, J.
    • Roberson, T.
  • Source: Journal of Environmental Quality
  • Volume: 37
  • Issue: 2
  • Year: 2008
  • Summary: Increased CO2 release from soils resulting from agricultural practices such as tillage has generated concerns about contributions to global warming, Maintaining current levels of soil C and/or sequestering additional C in soils are important mechanisms to reduce CO2 in the atmosphere through production agriculture. We conducted a study in northern Alabama from 2003 to 2006 to measure CO2 efflux and C storage in long-term tilled and non-tilled cotton (Gossypium hirsutum L.) plots receiving poultry litter or ammonium nitrate (AN). Treatments were established in 1996 on a Decatur silt loam (clayey, kaolinitic thermic, Typic Paleudults) and consisted of conventional-tillage (CT), mulch-tillage (MT), and no-tillage (NT) systems with winter rye [Secale cereale (L.)] cover cropping and AN and poultry litter (PL) as nitrogen sources. Cotton was planted in 2003, 2004, and 2006. Corti was planted in 2005 as a rotation crop using a no-till planter in all plots, and no fertilizer was applied. Poultry litter application resulted in higher CO2 emission from soil compared with AN application regardless of tillage system. In 2003 and 2006, CT (4.39 and 3.40 mu mol m(-2) s(-1), respectively) and MT (4.17 and 3.39 mu mol m(-2) s(-1), respectively) with, PL at 100 kg N ha(-1) (100 PLN) recorded significantly higher CO2 efflux compared with NT with 100 PLN (2.84 and 2.47 mu mol m(-2) s(-1), respectively). Total soil C at 0- to 15-cm depth was not affected by tillage but significantly increased with PL application and winter rye cover cropping. In general, cotton, produced with NT conservation tillage in conjunction with PL and winter rye cover cropping reduced CO2 emissions and sequestered more soil C compared with control treatments.
  • Authors:
    • Rodriguez-del-Bosque, L.
    • Salinas-Garcia, J.
  • Source: Journal of Entomological Science
  • Volume: 43
  • Issue: 2
  • Year: 2008
  • Summary: The effects of tillage, irrigation (10 cm each at 10- to 14-leaf stage, and silking and milk stages, and no supplemental irrigation) and fertilizer (NPK at 0:0:0 or 140:40:0 kg/ha) treatments on the incidence of lepidopteran insects and fungi infesting maize (cv. Pioneer 3025W) were studied in Tamaulipas, Mexico, during 2005-07. The tillage treatments consisted of mouldboard ploughing (discing stalks after harvesting, followed by mouldboard ploughing, discing and row establishment), subsoil-bedding (shredding stalks after harvesting, followed by subsoiling on row centres and establishment of beds), shred-bedding (shredding stalks after harvesting, followed by bedding on old rows), and no-tillage (shredding stalks after harvesting, and spraying 0.6 kg glyphosate and 0.72 kg 2,4-D/ha twice for weed control). Mouldboard ploughing represented conventional tillage, whereas subsoil-bedding and shred-bedding were reduced tillage systems. The lepidopteran species recorded were Helicoverpa zea (86%) and Spodoptera frugiperda (14%). The incidence of these pests was highest in 2006 (91.5%) and lowest in 2007 (49.3%). The most common fungi were Fusarium spp., the highest incidence of which was registered in 2005 (24.4%). The incidence of Aspergillus flavus and Ustilago maydis [ U. zeae] was less than 4.0% regardless of the year. The incidence of lepidopterans significantly varied between the irrigation levels only (greater pest population under dryland farming). Fusarium spp. and A. flavus occurred more frequently under no-tillage compared with other tillage practices. The incidence of Fusarium spp. was higher in irrigated than in dryland maize.
  • Authors:
    • Suyker, A. E.
    • Verma, S. B.
  • Source: Agricultural and Forest Meteorology
  • Volume: 148
  • Issue: 3
  • Year: 2008
  • Summary: In this paper, we present results from 4 years (May 2001-May 2005) of water and energy flux measurements made in a no-till, irrigated maize-soybean rotation system in eastern Nebraska, USA. The peak green leaf area index (LAI) reached 6.0 and 5.5 in maize (2001 and 2003, respectively) and 5.7 and 4.4 in soybean (2002 and 2004, respectively). The dependence of evapotranspiration (ET) on leaf area was consistent with previous studies. There was a nearly linear relationship between the daily ET/ET o (where ET o is the reference evapotranspiration over a grass reference crop) and LAI until a threshold LAI (between 3 and 4). Above this threshold LAI, the ET/ET o was virtually independent of LAI. The cumulative growing season (planting to harvest) evapotranspiration was 544 and 578 mm for maize, and 474 and 430 mm for soybean. The interannual variability in the growing season ET totals correlated very well with the number of days when the LAI was greater than 3. The non-growing season period (harvest to subsequent planting) contributed between 20 and 25% of the annual ET totals for both crops. The maximum canopy surface conductance ( Gsmax) was 29 mm s -1 for maize in both years, 41 mm s -1 for soybean in 2002 (peak LAI=5.7) and 36 mm s -1 for soybean in 2004 (peak LAI=4.4). The variability in Gsmax was largely explained by the leaf nitrogen concentration, consistent with the literature.