• 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.
  • Authors:
    • Rasaily, R. G.
    • Lu, C.
    • Li, H.
    • He, J.
    • Wang, Q.
    • Su, Y.
  • Source: Transactions of the Chinese Society of Agricultural Engineering
  • Volume: 28
  • Issue: 1
  • Year: 2012
  • Summary: In order to solve the problems of residue blocking and difficulty to open the furrow of no-till wheat planter in heavy corn residue cover fields in annual double cropping areas of the North China, a telescopic lever furrowing and anti-blocking unit was designed for no-till planter. Its key parameters were determined based on a band between orthogonal test and the structure analysis, and a telescopic lever furrowing and anti-blocking unit was used to conduct the field experiment. The field experiment showed that the telescopic lever furrowing and anti-blocking unit could solve the problem of straw blocking effectively and improve the seeding quality. Compared with the strip rotary-tilling anti-blocking unit, the telescopic lever furrowing and anti-blocking unit could reduce topsoil disturbance quantity by 21.5%; fuel consumption per unit area was reduced by 23.65% when the depth of furrow opening was 10 cm, which could reduce power consumption of tractor. Above all, the telescopic lever furrowing and anti-blocking unit has important value in extending no-tillage planter.
  • Authors:
    • Hoogmoed, W. B.
    • Oenema, O.
    • Cai D.
    • Jin, K.
    • Wu, X.
    • Zhao, Q.
    • Feng, Z.
    • Zhang, D.
    • Dai, K.
    • Wu, H.
    • Wang, X.
  • Source: Field Crops Research
  • Volume: 132
  • Year: 2012
  • Summary: Dryland farming in the dry semi-humid regions of northern China is dominated by mono-cropping systems with mainly maize ( Zea mays L.) or wheat ( Triticum aestivum), constrained by low and variable rainfall, and by improper management practices. Addressing these problems, field studies on tillage and residue management for winter wheat and spring maize were conducted at 4 sites in Linfen, Tunliu and Shouyang (Shanxi province) and Luoyang (Henan province). These studies (a.o.) explored the impacts of different tillage and residue application methods on soil physical conditions, water storage, water use, water use efficiency (WUE) and crop yields of wheat and maize. An analysis of the results of these studies is presented. Conservation tillage, comprising no-till as well as reduced tillage practices (subsoiling, deep ploughing) showed benefits which were more prominent in combination with residue application. Benefits compared to conventional tillage were found in the form of improved soil physical conditions, such as higher topsoil bulk densities but lower subsoil bulk densities. This resulted in a better water storage during the summer fallow or rainy season in winter wheat fields, and a better water conservation and soil protection in spring maize fields. Compared to conventional methods, reduced tillage gave yields around 13-16% higher in spring maize and round 9-37% higher in winter wheat. Yields under no-till were very close to those from conventional methods. Surface application of crop residue for maize was found to increase the risk for delayed seedling emergence, because of low temperatures, leading to a recommendation for incorporation of residue in combination with reduced tillage. For winter wheat, subsoiling in combination with straw mulching after harvest in summer every other two or three year, and no-till seeding is a promising practice for sandier soils and low rainfall conditions. For heavier clay loam soils, deep ploughing with straw mulching after wheat harvest in summer every other two or three year, and no-till seeding practice is recommended. For spring maize, deep ploughing with straw and fertilizers incorporation after harvest in fall, and no-till seeding practices are recommended. Subsoiling or no-till with residue mulching after harvest in fall, and no-till seeding practices in spring are also promising practices, the latter only in situations where low spring temperatures are not a problem. Continuous no-till is not recommended.
  • Authors:
    • Wei, T.
    • Cui, R.
    • Ding, R.
    • Yang, B.
    • Han, Q.
    • Liang, L.
    • Jia, Z.
    • Wang, X.
  • Source: Transactions of the Chinese Society of Agricultural Engineering
  • Volume: 28
  • Issue: 6
  • Year: 2012
  • Summary: A field experiment (2007-2010) was conducted at Weibei Dryland to determine the effects of different organic fertilizer rates on soil moisture and economic returns of maize (Zea mays L.). Organic fertilizer at rates of 0 (CK), 7500, 15 000 and 22 500 kg.hm -2 combined with the same rate of chemical fertilizer was applied into field plots. The results showed that manure treatments significantly increased soil moisture storage by 11.49%-21.63% compared with CK; high rate of manure treatment increased soil moisture storage by 9.09% than low rate of manure treatment during maize big trumpet period in the fourth year of fertilization (2010). High rate of manure treatment significantly increased the average soil moisture storage in 200 cm soil layer by 4.79%-7.65% compared with control. Medium rate of manure treatment had significantly higher average soil moisture storage in 200 cm soil layer by 6.50% than control in the fourth year of fertilization. Manure treatments significantly increased water use efficiency by 12.37%-37.55% compared with control. High and medium rates of manure treatments significantly increased water use efficiency in contrast with low rate of manure treatment. Soil conditions were no longer the major limiting factors for increasing water use efficiency with the manure application years increased. It is suggested that medium rate of manure treatment had an obvious effect on conserving moisture and increasing income of maize.
  • Authors:
    • Divito, G.
    • Sainz Rozas, H.
    • Echeverria, H.
    • Wyngaard, N.
  • Source: Soil & Tillage Research
  • Volume: 119
  • Year: 2012
  • Summary: Agricultural management practices, such as tillage and fertilization alter soil physical, chemical and biological properties over the medium term, which has a direct impact on the system's sustainability and crop performance. The aim of this work was to evaluate how fertilization with nitrogen (N), phosphorus (P), sulphur (S), micronutrients (Mi), liming (Li) and tillage systems affect soil properties in the medium term, and to measure the impact of these changes on maize ( Zea mays L.) yield. A seven-year experiment on a Typic Argiudoll in the Southern Pampas region of Argentina using seven fertilizations treatments (Control, N P, NS, PS, NPS, NPS+Mi, and NPS+Mi+Li) and two tillage systems - conventional tillage (CT) and no-till (NT) - was evaluated. Each sub-plot was analyzed to determine physical parameters - bulk density (BD) and aggregate stability (AS)-, biological parameters - total organic carbon (TOC), carbon in the particulate fraction (COP), anaerobically incubated nitrogen (AN), total nitrogen (TN) and nitrogen in the particulate fraction (PN) - and chemical parameters - nitrate, available phosphorus, sulphate and pH - at different depths. Also, maize yield was measured in the final year without fertilizer application, in order to evaluate the effects of soil changes on this crop. Among the physical parameters, the only differences found were in BD between tillage systems in the 0-5 cm layer (1.28 g cm -3 in NT and 1.15 g cm -3 in CT). Biological parameters were unaffected by fertilization treatments. However, tillage systems modified many of them in the 0-5 cm layer: COT (17 Mg ha -1 in CT and 21 Mg ha -1 in NT), POC (2.4 Mg ha -1 in CT and 4.5 Mg ha -1 in NT), TN (1.4 Mg ha -1 in CT and 1.8 Mg ha -1 in NT), PN (0.3 Mg ha -1 in CT and 0.5 Mg ha -1 in NT) and AN (56 mg kg -1 in CT and 79 mg kg -1 in NT). These differences were not significant when the 5-20 cm depth was analyzed. Chemical properties such as pH (5.7 in treatments with N; 6.1 without N, and 6.4 with N and lime) and P Bray content were modified (35 mg kg -1 in treatments with P and 13 mg kg -1 without P). In both cases, there was interaction with the tillage system, with significant stratification under NT. Maize yield was only affected by residual P; there were no other effects of medium-term fertilization or tillage systems.
  • Authors:
    • Li, F.
    • Gan, Y.
    • Li, X.
    • Si, J.
    • Xiong, Y.
    • Liu, C.
    • Jin, S.
    • Zhou, L.
  • Source: Field Crops Research
  • Volume: 126
  • Year: 2012
  • Summary: Understanding plant-soil relationships may help maximize crop productivity while maintaining and improving soil quality. Field experiments were conducted in 2006 and 2007 at the Dryland Agricultural Experimental Station of the Loess Plateau, Lanzhou University, China, to determine the effects of various ridge-furrow and plastic-mulching techniques on the growth and yield of maize ( Zea mays L.) and soil biochemical properties. Five treatments were designed: (1) flat-plot sowing without ridge-furrow mulching (CK), (2) large (80 cm) and small (40 cm) ridges alternated and fully mulched with plastic (DRM), (3) on-furrow sowing with plastic mulch applied only on the ridge at a row spacing of 60 cm and 40 cm alternatively (RM), (4) flat-plot sowing with plastic mulch at a row spacing of 60 cm and 40 cm alternatively (NM), and (5) flat-plot sowing with plastic mulch at a row spacing of 80 cm and 40 cm alternatively (WM). The results showed that film mulching enhanced soil microbial biomass; where microbial biomass carbon (MBC) in the DRM treatment reached 633 mg kg -1 at harvest in 2007, three times the MBC of the CK. The MBC:SOC ratios were 8.8%, 7.1%, 5.7% and 5.4% in DRM, RM, NM and WM, respectively. The ridge-furrow with plastic-mulching increased soil light fraction carbon (LFOC) in both years, averaging up to 1.04 g kg -1 at harvest. Underground plant biomass increased substantially in the mulching treatments, especially in DRM. Positive correlations were found between total biomass and LFOC, between MBC and LFOC, and between MBC and available phosphorus (AP), but a negative correlation between SOC and soil mineral nitrogen (MN). The carbon to phosphorus (C/P) ratio was highest in DRM among treatments, but the content of SOC, MN, and C/N ratio in DRM was lowest, suggesting that the DRM treatment strengthened the interactions between maize and soil, and that the increased content of LFOC with time provides a basis for increasing productivity in future years. In conclusion, the ridge-furrow and plastic-mulching technique brought about a challenge in maintaining soil fertility, but this technology provides a potential opportunity of substantially increasing crop yields in semiarid rainfed regions.
  • Authors:
    • Reinhardt, C. F.
    • Bezuidenhout, S. R.
    • Whitwell, M. I.
  • Source: Weed Research
  • Volume: 52
  • Issue: 2
  • Year: 2012
  • Summary: No information is available on the effect of cover crops on weed growth in maize production in KwaZulu-Natal, South Africa. In a field experiment, the influence of two preceding cover crops, stooling rye and annual ryegrass, on the growth of maize and the weed Cyperus esculentus were compared with herbicides and weed control by hoeing. Maize emergence and early growth were delayed in the presence of physical residues of both cover crop species, especially annual ryegrass. Growth of C. esculentus was significantly inhibited in the inter-row maize planting lines by the cover crops for the first 16 days after maize emergence, but this effect had diminished by day 28. In a pot experiment, the influence of the same two cover crops on maize and C. esculentus growth was evaluated together with oats and two additional annual ryegrass cultivars. Here, the growth of maize and C. esculentus were suppressed, especially by the root residues of the annual ryegrass, in particular the cultivar Midmar. Chemical analysis of the leachate of the root residues indicated the presence of phenolic acids and benzoxazolin-2(3 H)-one. To achieve effective weed control, a weed management strategy combining the mulch retained on the soil surface, with a possible reduction in the type and amount of herbicide, should be implemented.
  • Authors:
    • Pauletti, V.
    • Favaretto, N.
    • Molin, R.
    • Mellek, J. E.
    • Dieckow, J.
    • Da-Silva, V. L.
    • Vezzani, F. M.
  • Source: REVISTA BRASILEIRA DE CIENCIA DO SOLO
  • Volume: 36
  • Issue: 3
  • Year: 2012
  • Summary: The quality of no-tillage systems depends on an adequate soil management that promotes soil structure improvements. This is associated to the cropping system adopted. This study investigated the effect of long-term no-tillage systems (18 years) on the structural quality of a sandy-clay to clay Oxisol (Latossolo Vermelho) in the region of Campos Gerais, Parana, Brazil. Five cropping systems were assessed: wheat-soybean [Wt-So], black oat-maize-wheat-soybean [Ot-Mz-Wt-So], vetch-maize-wheat-soybean [Vt-Mz-Wt-So], ryegrass-maize-ryegrass-soybean [Rg-Mz-Rg-So]; and alfalfa-maize [Alf-Mz]. Soil was sampled from the layers 0-5, 5-10 and 10-20 cm, in cylinders and in blocks with undisturbed structure. In the 0-5 cm layer, bulk density was lowest in the Ot-Mz-Wt-So (0.96 Mg m -3) and Vt-Mz-Wt-So systems (0.93 Mg m -3). In the 5-10 and 10-20 cm layers, the bulk density tended to be lowest in Alf-Mz systems (1.14 and 1.17 Mg m -3, respectively). A similar trend was observed for macroporosity, which in the top layer was greater in Ot-Mz-Wt-So (0.29 m 3 m -3) and Vt-Mz-Wt-So (0.30 m 3 m -3) and in the 5-10 and 10-20 cm layers tended to be greater in the Alf-Mz system (0.19 m 3 m -3). No clear trend was observed for microporosity. The saturated hydraulic conductivity was directly related with macroporosity, and was highest for Vt-Mz-Wt-So in the 0-5 cm layer (224 mm h -1) and Alf-Mz in the layers 5-10 (170 mm h -1) and 10-20 cm (147 mm h -1). In the Vt-Mz-Wt-So system, the mean weight diameter of aggregates was lowest in the 0-5 cm layer (2.39 mm) and highest (3.04 mm) in the Wt-So. The highest cone index values were observed in the Wt-So system, with over 1.5 MPa in the 7.5-22.5 cm layer. The compaction degree was lowest in the Alf-Mz system (0.2 MPa cm). Results were attributed mainly to the role of the crop roots of the systems and to the intensity of machinery traffic. Considering the 0-20 cm layer as a whole, the capacity to promote soil structural quality improvements was greater for the semi-perennial Alf-Mz system than for systems based on annual species. Bi-annual rotation systems, based on cover crops such as black oat and vetch, promote soil structural quality improvements compared to the wheat - soybean succession.
  • Authors:
    • Pannacci, E.
    • Onofri, A.
    • Graziani, F.
    • Tei, F.
    • Guiducci, M.
  • Source: European Journal of Agronomy
  • Volume: 39
  • Year: 2012
  • Summary: Long-term effects of organic (ORG) and conventional low-input (CONV) farming systems on size and composition of weed seedbank were assessed in 2007 in central Italy, in an on-farm experiment set up in 1996. In this experiment, six rotations (R1-R6) were considered, basically consisting on the same crop sequence with different starting points, i.e. (1) legume crop (soybean/field bean/common pea), (2) vegetable crop (pepper/melon), (3) winter cereal (soft/durum wheat), (4) summer cereal (maize) (5) industrial vegetable (processing tomato), (6) winter cereal (soft/durum wheat). All rotations were established both in ORG and in CONV, in strict adherence to EU regulations (ORG: EU reg. 2092/91; CONV: EU reg. 2078/92). Intercrops with green manuring purposes were included in ORG, while weed control was performed mechanically in ORG and chemically/mechanically in CONV. Weed seedbank was determined on 10 soil samples (0-0.30 m depth) in each plot and seeds were directly extracted, identified and counted. In all rotations, the adoption of ORG resulted in a significant increase in weed seedbank density, particularly in the case of summer weed species ( Portulaca oleracea L., Amaranthus retroflexus L. and Chenopodium album L.), which are more competitive and difficult to control in summer crops under organic farming systems in the Mediterranean climates. Small differences between ORG and CONV were found in terms of number of weed species (23 in ORG and 20 in CONV, on average), but the index of diversity in CONV was on average higher than in ORG. Furthermore, the most dominant weeds in CONV represented a lower percentage of total seedbank (40%, 23% and 5%, respectively, for P. oleracea, A. retroflexus and C. album in CONV and 56%, 32% and 4% for the same three weeds in ORG). These results confirm that the wider availability of effective weed control methods in integrated low-input farming systems (CONV) is helpful to maintain a low seedbank size, with a lower dominance structure. However, the adoption of ORG systems based on long rotation cycles, very competitive crops and accurate weed control, especially at the beginning of the ORG management, may be sustainable in the long run, in terms of potential weed infestation levels.
  • Authors:
    • Rodrigues, J. G. L.
    • Fernandes, D. M.
    • Bicudo, S. J.
    • Nascimento, F. M.
    • Fernandes, J. C.
    • Furtado, M. B.
  • Source: Revista Brasileira de Ciencias Agrarias
  • Volume: 7
  • Issue: 1
  • Year: 2012
  • Summary: The main goal of this research was to evaluate the response of maize crop in succession to maize+oat crops, with the anticipation of the increasing doses of nitrogen application in the oat culture, in no-tillage system. The experiment was carried out under field conditions at FCA/UNESP, Botucatu Campus, Sao Paulo, Brazil. The experimental design was arranged in randomized blocks with four replications, in split-plots. The plots were the nitrogen doses applied on the oat crop (0, 20, 40 e 60 kg ha -1), and split-plots, the nitrogen doses applied in the cover (60, 80, 100 e 120 kg ha -1), divided into two different crop stages of the maize crop. The dry matter weight and the C/N ratio were assessed on the oat and maize crops. On the maize crop, the plant nitrogen was quantified before the first covering and 15 days after the second covering, when the dry matter weight of the maize plants was determined. After the harvest, the yield was also calculated. Results indicate that the maize development and yield under no-till system were related to the straw C/N ratio, and the maize crop response to the anticipated N fertilization anticipation varied according to the N doses and application periods. The dry matter weight of the maize plants were influenced by the rates and periods of N applications.