• Authors:
    • Topa, D.
    • Cara, M.
    • Jitareanu, G.
    • Raus, L.
  • Source: Annals of the University of Craiova - Agriculture, Montanology, Cadastre Series
  • Volume: 40
  • Issue: 1
  • Year: 2010
  • Summary: The project aims the sustainable development in Romania, soil, water and carbon conservation, and counter-balances the effects of global climate change. Research carried out aimed at developing fundamental knowledge through in-depth inquiries of soil quality indicators of Moldavian Plain, regarding integrated management of soil and water. Research carried out also aimed to quantify the influence of agricultural technologies on physic, hydric, thermic, nutrient and biological soil regime, and ecological impact of these changes on ecological, energetically, hydrological, biogeochemical and breathing soil function, in specific areas of Moldavian Plain. The experiment was conducted at the Didactic Station of the "Ion Ionescu de la Brad" University of Agricultural Sciences and Veterinary Medicine of Iasi, Ezareni Farm, during Analele Universitatii din Craiova, seria Agricultura - Montanologie - Cadastru Vol. XL/1 2010 farming years 2007-2009. The experimental site is located in the East part of Romania on a chambic chernozem, with a clay-loamy texture, 6.8 pH units, 3.7% humus content and a medium level of fertilization. The soil has high clay content (38-43%) and is difficult to till when soil moisture is close to the wilting point (12.2%). We have investigated three variants of soil tillage system - conventional tillage, minimum tillage and no-till - in the crop rotation made of wheat and raps. This paper presents the results obtained in winter wheat growing as concerns the influence of the tillage method on some soil physical characteristics. Tillage system modify, at least temporarily, some of the physical properties of soil, such as soil bulk density, penetration resistance, soil porosity and soil structural stability. All the tillage operation was significantly different in heir effects on soil properties. The results indicate that soil tillage systems must be adjusted to plant requirements for crop rotation and to the pedoclimatic conditions of the area.
  • Authors:
    • Sainju, U. M.
    • Jabro, J. D.
    • Caesar-TonThat, T.
  • Source: Journal of Environmental Quality
  • Volume: 39
  • Issue: 3
  • Year: 2010
  • Summary: Management practices are needed to reduce dryland sod CO(2) emissions and to increase C sequestration We evaluated the effects of tillage and cropping sequence combinations and N fertilization on dryland crop biomass (stems + leaves) and sod surface CO(2) flux and C content (0- to 120-cm depth) in a Williams loam from May to October, 2006 to 2008, in eastern Montana. Treatments were no-tilled continuous malt barley (Hordeum vulgaris L) (NTCB), no-tilled malt bailey pea (Pivot; sativum L) (NTB-P), no-tilled malt barley fallow (NTB-F), and conventional-tilled malt barley fallow (CTB-F), each with 0 and 80 kg N ha(-1) Measurements were made both in Phase I (malt barley in NTCB, pea in NTB-P, and fallow in NTB-F and CTB-F) and Phase II (malt barley in all sequences) of each cropping sequence in every year Crop biomass varied among years. was greater in the barley than in the pea phase of the NTB-P treatment, and greater in NTCB and NTB-P than in NTB-F and CTB-F in 2 out of 3 yr Similarly biomass was greater with 80 than with 0 kg N ha(-1) in 1 out of 3 yr. Soil CO(2) flux increased from 8 mg C m(-2) h(-1) in early May to 239 mg C m(-2) h(-1) in mid-June as temperature increased and then declined to 3 mg C m(-2) h(-1) in September. October Fluxes peaked immediately following substantial precipitation (>10 mm). especially in NTCB and NTB-P Cumulative CO(2) flux from May to October was greater in 2006 and 2007 than in 2008, greater in cropping than in fallow phases, and greater in NTCB than in NTB-F. Tillage did not influence crop biomass and CO(2) flux but N fertilization had a variable effect on the flux in 2008. Similarly, soil total C content was not influenced by treatments Annual cropping increased CO(2) flux compared with crop fallow probably by increasing crop residue returns to sods and root and rhizosphere respiration Inclusion of peas in the rotation wills malt barley in the no-till system, which have been known to reduce N fertilization rates and sustain malt barley yields, resulted in a CO(2) flux similar to that in the CTB-F sequence
  • Authors:
    • Sandor, M.
    • Domuta, C.
    • Vuscan, A.
    • Domuta, C.
    • Samuel, A.
  • Source: Research Journal of Agricultural Science
  • Volume: 42
  • Issue: 3
  • Year: 2010
  • Summary: The importance of phosphatase for plant nutrition has repeatedly been pointed out. In most soils, the organically bound P-fraction is higher than the inorganic. Phosphorus uptake by plants requires mineralization of the organic P-component by phosphatases to orthophosphate. Phosphatases are inducible enzymes that are produced predominantly under conditions of low phosphorus availability. Phosphatases are excreted by plant roots and by microorganisms. Microbial phosphatases dominate in soils. The phosphomonoesterases, so-called phosphatases differ in their substrate specificity and their pH optimum. One can thus differentiate between acid and alkaline phosphatases in the soil. Phosphatase activities were determined in the 0-20-, 20-40- and 40-60-cm layers of a preluvosoil submitted to a complex tillage (no-till and conventional tillage), crop rotation (2- and 3-crop rotations) and fertilisation [mineral(NP) fertilisation and farmyard-manuring] experiment. It was found that the activities decreased in the order: acid phosphatase activity > alkaline phosphatase activity. Each activity decreased with increasing sampling depth. No-till-in comparison with conventional tillage - resulted in significantly higher soil phosphatase activities in the 0-20-cm layer and in significantly lower activities in the deeper layers. The soil under maize or wheat was more phosphatase-active in the 3- than in the 2-crop rotation. In the 2-crop rotation higher soil phosphatase activities were recorded under wheat than under maize. Farmyard-manuring of maize - in comparison with its mineral fertilisation - led to a significant increase in each activity.
  • Authors:
    • Singh, V. K.
    • Sah, A. K.
    • Prakash, O.
    • Singh, R. K.
    • Singh, S. N.
  • Source: Outlook on Agriculture
  • Volume: 39
  • Issue: 3
  • Year: 2010
  • Summary: Rice-wheat is the most commonly employed cropping system on around 14 million hectares of land extending across the Indo-Gangetic Plain (IGP). The IGP region covers the South Asian countries of Pakistan (2.2 million ha), India (10.5 million ha), Nepal (0.5 million ha) and Bangladesh (0.8 million ha). The major challenge facing the IGP's rice-wheat cropping system is to sustain long- term productivity. This system has a pivotal role in the food security and livelihoods of millions of farmers and workers of populous countries such as India, particularly in central Uttar Pradesh. The system's productivity and economic gains have been consistently decreasing, mainly because of the delayed sowing of wheat after the rice harvest and the fatigued soil condition. The region's farmers lose valuable time for pre-sowing irrigation and field preparation due to the gap of two to three weeks between the harvesting of rice and the planting of wheat. If wheat sowing is delayed beyond the optimal time (by late November), yields plummet at the rate of 30 kg per ha per day. The adoption of resource conservation technologies, such as zero tilled wheat sowing, is considered essential to maintain the productivity of the rice-wheat cropping system. Economic analysis of data for two years from six on- farm demonstrations shows that the zero tillage method of wheat cultivation is the most economical and attractive option for the farming community of central Uttar Pradesh. A high grain yield and reduced cost of cultivation per hectare, reduction in the density of weeds, especially Phalaris minor, and greater water saving were noted in zero tilled wheat sowings compared with conventional practices. As a result of field demonstrations and farmer training programmes, the introduction of zero till drill wheat sowing has expanded rapidly and has made significant contributions to the tillage revolution in the study area.
  • Authors:
    • Maul, J. E.
    • Buyer, J. S.
    • Austin, E. E.
    • Treonis, A. M.
    • Spicer, L.
    • Zasada, I. A.
  • Source: Applied Soil Ecology
  • Volume: 46
  • Issue: 1
  • Year: 2010
  • Summary: Soil microorganisms (bacteria, fungi) and microfauna (nematodes, protozoa) have been shown to be sensitive to organic amendments, but few experiments have investigated the responses of all these organisms simultaneously and across the soil profile. We investigated the impact of organic amendment and tillage on the soil food web at two depths in a field experiment. Over three growing seasons, field plots received seasonal organic amendment that was either incorporated into the soil (tilled) or not (no-till) as part of a tomato/soybean/corn cropping system. Un-amended, control plots that were either tilled or no-till were also included. We hypothesized that the addition of amendments would have a bottom-up effect on the soil food web, positively influencing the abundance of microorganisms, protozoa, and nematodes, primarily in the surface layers of the soil, but that this effect could be extended into deeper layers via tillage. Organic amendment had positive effects on most measured variables, including organic matter, respiration, protozoan and nematode density, and the abundance of PLFA biomarkers for bacteria and fungi. These effects were more pronounced in the 0-5 cm depth, but most variables increased with amendment in the deeper layer as well, especially with tillage. Denaturing Gradient Gel Electrophoresis (DGGE) of bacterial rDNA fragments indicated that distinct bacterial communities were selected for among tillage and amendment treatments and depths. Nematode faunal indices were not influenced by amendment, however. Increased nematode density in amended soils encompassed all trophic groups of free-living nematodes, with the greatest response among fungal-feeders, particularly with tillage. Increased biomass of microorganisms and decomposer microfauna in amended, tilled soils (0-5 cm depth) corresponded with a decline in the abundance of plant-parasitic nematodes. In control soils (0-5 cm depth), tillage reduced the relative abundance of fungal-feeding nematodes and increased the density of bacterial-feeding nematodes, in particular nematode species contributing to the Enrichment Index. When combined with organic amendment however, tillage was associated with increases in fungal-feeding nematodes and fungal biomarker PLFA. The results of this study suggest that when combined with amendment, tillage enhances the soil food web beyond the effect of amendment alone and is associated with declines in plant-parasitic nematodes.
  • Authors:
    • Li, G.
    • Luo, C.
    • Wang, X.
    • Niu, Y.
    • Gao, C.
    • Nan, Z.
    • Shen, Y.
    • Yang, J.
  • Source: Acta Prataculturae Sinica
  • Volume: 19
  • Issue: 1
  • Year: 2010
  • Summary: The effects of conventional tillage (t), conventional tillage with stubble retention (ts), no-tillage (nt), and no-tillage with stubble retention (nts) treatment on crop yield, soil total nitrogen and carbon, total organic carbon, oxidizible organic carbon, and carbon pool management index (CPMI) were investigated within a maize-wheat-soy rotation system in the western Loess Plateau. Total crop yield for ten harvests during the years 2001 to 2007 under ts and nts treatments increased by 3.63 and 1.62 g/kg compared with conventional tillage, but decreased by 2.48 g/kg on the nt treatment. Total nitrogen contents under nts treatment were 15.4%, 30.2% and 16.2% higher than t, ts and nt treatments. Total carbon under nts treatment was significantly increased by 2.04 g/kg and total organic carbon were 2.50, 1.56 and 1.70 g/kg higher than under t, ts and nt treatment, respectively. Easily oxidized organic carbon under nts was 2.13 g/kg higher than under t treatment. TN/TC decreased by 12.75%, 15.97%, 6.87% and 24.16% under t, ts, nt and nts treatments. The CPMI under ts, nt and nts were 12.6%, 20.1% and 46.6% higher than under t, both stubble retention and no-till were beneficial to increasing the soil organic carbon content and improving the quality of the carbon pool.
  • Authors:
    • Drury, C. F.
    • Yang, X. M.
    • Zhang, Z. D.
    • Reynolds, W. D.
    • Zhao, L. P.
  • Source: Canadian Journal of Soil Science
  • Volume: 90
  • Issue: 4
  • Year: 2010
  • Summary: Soil organic matter is a heterogeneous mixture of organic substances with different compositions and stabilities. To enhance soil organic carbon (SOC) sequestration, it is helpful to understand the distribution of SOC among the soil particle size fractions, the stabilities of the SOC within each fraction, and the influence of management practices, such as tillage, on SOC mineralization. Hence, the objectives of this study were to determine the distribution and mineralization rate of active SOC in the sand (53-2000 m), silt (2-53 m) and clay ( silt > sand for all three tillages. On a whole-soil basis and averaged over the tillage treatments, 55.8% of the SOC was in the clay size fraction, 37.2% was in the silt fraction and 7.0% was in the sand fraction. Carbon mineralization rate in the incubated samples decreased over time, and was related to both particle size fraction and tillage practice. There was very good agreement between a first-order decay model ( Ct = C1+ C0(1- e-kt )) and measured SOC mineralization rates for all size fractions and tillages. The C mineralization data indicated that: (1) the SOC in the clay and sand fractions was more decomposable than the SOC in the silt fraction; and (2) the SOC associated with the clay and silt fractions was more readily decomposable under no-till than under mouldboard plough.
  • Authors:
    • Boykin, D.
    • Balkcom, K.
    • Arriaga, F.
    • Balkcom, K.
  • Source: Agronomy Journal
  • Volume: 102
  • Issue: 2
  • Year: 2010
  • Summary: Increased production costs and potential benefits of maintaining surface residue has renewed interest in conservation tillage systems for peanut ( Arachis hypogaea L.) production. We determined surface residue cover from rye ( Secale cereale L.) or oat ( Avena sativa L.) cover crops after two strip tillage systems (narrow vs. wide) and planting operations with different row configurations (single vs. twin). We also compared plant populations, yields, and total sound mature kernels for three peanut cultivars ('ANorden', 'AP-3', and 'Georgia-02C') across each treatment combination. Seven site-years were examined across similar soil types in Alabama and northern Florida during the 2004 to 2006 growing seasons. The highest surface residue counts were for the narrow tillage system planted in single rows. Final plant stands were influenced by an interaction between cultivar and row configuration, with 'ANorden' planted in single rows below recommended rates. Peanut yields were affected by strip tillage system and row configuration, but differences among cultivars were also observed. Twin-row peanut yields were 5% greater than single-row peanut yields in the narrow strip tillage system but were similar across strip tillage systems. Cultivars 'AP-3' and 'Georgia-02C' yielded 20% higher than 'ANorden'. Total sound mature kernels were only affected by peanut cultivar, with the cultivar 'Georgia-02C' producing the highest-quality peanut, followed by 'ANorden' and 'AP-3'. These results indicate that growers interested in using twin rows for peanut production can also take advantage of a narrow strip tillage system that maximizes surface residue coverage and subsequent benefits.
  • Authors:
    • Jasso-Chaverria, C.
    • Martinez-Gamino, M.
  • Source: Proceedings of the 19th World Congress of Soil Science: Soil solutions for a changing world, Brisbane, Australia, 1-6 August 2010. Symposium 3.2.1 Highland agriculture and conservation of soil and water
  • Year: 2010
  • Summary: Among the main constraints to adopting conservation tillage in the semiarid zones in Mexico's north-central region are: low acceptance among farmers, need of specialized machinery, use of herbicides, and above all, the need to utilize stubble to feed animals. The objective of this study was to assess the effect of different tillage methods in an irrigated corn-oat rotation system on corn grain, stubble, and forage oat yield. Seven tillage methods were evaluated: (1) traditional plow and disk (P+D), (2) disturbing the upper 0-4 in layer (D), (3) without disturbing the upper 0-4 in layer (ND), (4) zero tillage with 0% soil cover (ZT+0%SC), (5) zero tillage with 33% soil cover (ZT+33%SC), (6) zero tillage with 66% soil cover (ZT+66%SC), and (7) zero tillage with 100% soil cover (ZT+100%SC). In each year from 1996 to 2007, corn was sowed on the spring while forage oat was grown during the fall-winter season. Corn grain yield results showed statistical differences among treatments (p≤0.05), where ZT+66%SC was the best treatment, surpassing by 90% the corn yield registered with P+D. The statistical analysis for corn stubble yield showed no differences (p≥0.05) among treatments. With ZT+66%SC, corn stubble production was increased 3.448 ton/ha compared with that of P+D, indicating that farmers can use 2.0 ton ha -1 to cover at least 33% of the soil surface. Forage oat yields within the seven treatments were not statistically different ( P≥0.05), but all ZT treatments were no-till seeded. Our conclusions are that corn and forage oat can be no-till seeded, increasing corn production and keeping stable production of forage oat. These results can be used to provide evidence to farmers of the benefits of adopting conservation tillage.
  • Authors:
    • Dube, R.
    • Dhyani, S.
    • Ratan, S.
    • Sharma, A.
  • Source: Indian Journal of Agronomy
  • Volume: 55
  • Issue: 4
  • Year: 2010
  • Summary: A field experiment was conducted at Selakui, Dehradun from 2001 to 2004 to study the effect of tillage, viz. conventional tillage (CT) and minimum tillage (MT); and weed-control practices, viz. chemical and mechanical weeding along with legume mulching, viz. in situ grown sunnhemp ( Crotalaria juncea L) and subabul [ Leucaena leucocephala (Lam.) de Wit] on soil moisture conservation, crop productivity and soil health in maize ( Zea mays L)-wheat ( Triticum aestivum L. emend Fiori & Paol.) cropping system. CT gave higher grain yield of maize (+0.11 to 0.17 t/ha), but wheat performed equally well under CT (2.48 t/ha) and MT conditions (2.36 t/ha). Chemical weeding with herbicides (alachlor in maize and isoproturon in wheat) resulted in 7.8 and 9.9% higher yield of maize and wheat, respectively over mechanical weeding. Beneficial effect of live mulching with sunnhemp or Leucaena was similar (12.3-14.7%), while their combined application increased the maize yield by 19.1% over no mulching. Further, enhanced soil moisture conservation due to mulching at maize harvest led to greater productivity of wheat by 16.1% with sunnhemp or Leucaena, and 27.0% with sunnhemp+ Leucaena. Nitrogen uptake of maize and wheat increased significantly with chemical weeding and legume mulching, but tillage practices made no effect on wheat while in maize it was lower under MT. Wheat gave 4-5 times more net returns than maize, and the net B:C ratio of the system was >1.0 with chemical weeding and legume mulching. Tillage and weed-control practices made no effect on organic C and total N status of soil but legume mulching improved these parameters and reduced bulk density associated with increased infiltration rate. It was concluded that CT along with legume mulching in maize and MT in wheat, and chemical weeding of both the crops was beneficial for improving moisture and nutrient conservation, and achieving higher productivity and profitability of maize-wheat cropping system under Doon valley conditions.