Estimation of decay constants for crop residues measured over 15 years in conventional and reduced tillage systems in a coarse-textured soil in southern Ontario

2011 ◽  
Vol 91 (6) ◽  
pp. 985-995 ◽  
Author(s):  
Ron Beyaert ◽  
R. Paul Voroney

Beyaert, R. P. and Voroney, R. P. 2011. Estimation of decay constants for crops residues measured over 15 years in conventional and reduced tillage systems in a coarse-textured soil in southern Ontario. Can. J. Soil Sci. 91: 985–995. Crop residues are the primary means of sustaining soil organic matter levels in agricultural soils. This study was undertaken to determine the effects of tillage practices on the rate of decomposition of crop residues over a 15-yr period under field conditions in southern Ontario. Microplots were amended with14C-labelled above-ground residues of five annual agricultural crops: corn (Zea mays L.), soybean (Glycine max L.), winter wheat (Triticum aestivum L.), winter rye (Secale cereale L.) and tobacco (Nicotiana tobaccum L.). The crop residues were added to the soil immediately following harvest during the 1990 growing season using a simulated conventional mouldboard plough–disc management (CT) or conservation tillage management (RT), and the amounts of crop residues remaining were measured periodically. The rate of decomposition of the labile C was positively correlated to the levels of hot-water soluble C and N content and negatively correlated to the C:N ratio and hemicellulose concentration of the residues. Decomposition of the residue C was greater under CT during the initial phase of decomposition, indicating that the incorporated residues were exposed to a more favourable environment for microbial activity compared with surface-applied residues. Kinetic analysis of residue decomposition showed that residues managed under CT had a larger labile component and faster rate of decomposition and a smaller resistant component with a slower decomposition rate than RT. Comparisons of models describing the decomposition of combined crops/tillage practices did not describe the decomposition process as well as models for individual crop/tillage combinations.

Agronomy ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1276
Author(s):  
Vaida Steponavičienė ◽  
Aušra Marcinkevičienė ◽  
Lina Marija Butkevičienė ◽  
Lina Skinulienė ◽  
Vaclovas Bogužas

The composition of weed communities in agricultural crops is dependent on soil properties and the applied agronomic practices. The current study determined the effect of different tillage systems and crop residue on the soil weed community composition. The research programme encompassed 2013–2015 in a long-term field experiment located in the Experimental Station of Vytautas Magnus University in Lithuania. The soil type in the experimental field was qualified as Endocalcaric Stagnosol (Aric, Drainic, Ruptic, Amphisiltic). Weeds were categorised into communities according to soil pH, nitrogen and moisture indicators. The results of investigations were grouped using cluster analysis. Agricultural crops were dominated by different weed species depending on the soil pH and moisture. Weed species were relatively more frequent indicating nitrogen-rich and very nitrogen-rich soils. In the reduced tillage and no-tillage systems, an increase in the abundance of weed species indicating moderate acidity and low acidity, moderately wet and wet, nitrogen-rich and very nitrogen-rich soils was observed. The application of plant residues decreased the weed species abundance. In the reduced tillage and no-tillage systems, the quantitative distribution of weed was often uneven. By evaluating the association of weed communities with groups of different tillage systems with or without plant residues, their control can be optimised.


2018 ◽  
Vol 10 (9) ◽  
pp. 3273 ◽  
Author(s):  
Shokoofeh Khorami ◽  
Seyed Kazemeini ◽  
Sadegh Afzalinia ◽  
Mahesh Gathala

Natural resources are the most limiting factors for sustainable agriculture in Iran. Traditional practices are intensive tillage that leads to a negative impact on crop productivity and soil properties. Conservation agriculture including tillage reductions, better agronomy, and improved varieties, showed encouraging results. The goal of this study was to test combined effect of tillage practices and wheat (Triticum aestivum L.) genotypes on soil properties as well as crop and water productivity. The experiment was conducted at Zarghan, Fars, Iran during 2014–2016. Experimental treatments were three-tillage practices—conventional tillage (CT), reduced tillage (RT), and no tillage (NT)—and four wheat genotypes were randomized in the main and subplots, respectively using split-plot randomized complete block design with three replications. Results showed NT had higher soil bulk density at surface soil, thereby lower cumulative water infiltration. The lowest soil organic carbon and total nitrogen were obtained under CT that led to the highest C:N ratio. Reduced tillage produced higher wheat yield and maize (Zea mays L.) biomass. Maximum irrigation water was applied under CT, which leads lower water productivity. The findings are based on short-term results, but it is important to evaluate medium- and long-term effects on soil properties, crop yields and water use in future.


2011 ◽  
Vol 38 (1) ◽  
pp. 41-47 ◽  
Author(s):  
Chad B. Godsey ◽  
Jeffrey Vitale ◽  
Phil G. Mulder ◽  
Jon-Joseph Q. Armstrong ◽  
John P. Damicone ◽  
...  

Abstract Oklahoma growers have increased their adoption of strip tillage (strip-till) and no tillage (no-till) systems as a means of reducing production costs and conserving soil resources. An experiment was conducted over three years to study the effects of three tillage systems [(conventional till (CT), no-till (NT), and strip-till (ST)] on pod yield, peanut grade, pest pressure, and economic profitability. Insect, disease, and weed incidence were determined in each year of the study. Peanut yield and grade were determined by mechanically harvesting the plot. No consistent differences were detected between NT and CT in peanut grade or yield when tillage systems were combined across years. In addition, no consistent differences were observed in disease incidence and insect populations. Economic analysis indicated that the NT system saved $93 ha−1 and generated $179 ha−1 more revenue compared to the CT system. Reduced tillage practices, especially NT, seem to be a good fit for SW peanut production areas.


1974 ◽  
Vol 54 (2) ◽  
pp. 171-178 ◽  
Author(s):  
E. G. BEAUCHAMP ◽  
I. HUSSAIN

Brown heart sometimes occurs in rutabagas (Brassica napobrassica Mill.) grown on some southern Ontario soils even though a recommended quantity of B fertilizer has been applied. Fourteen field experiments were conducted on growers' fields over a 4-yr period to determine the cause of this phenomenon. Brown heart occurred when the hot-water-soluble B content of the soil decreased below approximately 1.3 ppm although there were a few exceptions. An application of 4.5 kg B/ha as borax did not completely overcome the brown-heart condition in a majority of the experiments. The B concentration in the third or fourth leaf from the centre of the whorl was not related to brown-heart incidence. However, it was found that a B concentration of less than 18 ppm in the roots was generally associated with brown-heart incidence. Although there was no clear relationship between the Ca/B ratio in the leaf blades and brown-heart incidence, there was an increase in brown-heart incidence as the Ca/B ratio in the roots increased above 170. In three experiments, an application of 224 kg Na/ha as NaCl significantly increased brown-heart incidence, whereas in a fourth experiment there was a significant decrease. There was some evidence that the Na may slightly decrease the B concentration. Also the Ca concentration increased as the Na concentration increased in rutabaga tissues thereby affecting the Ca/B ratio and possibly brown-heart incidence. There was also evidence that, in the root tissues, the Ca/B ratio was inversely related to the K concentration. It was concluded that the effectiveness of B in decreasing brown-heart incidence was related to the Ca concentration in rutabaga plants.


1993 ◽  
Vol 73 (1) ◽  
pp. 51-59 ◽  
Author(s):  
D. A. Angers ◽  
N. Samson ◽  
A. Légère

Crop rotations and tillage practices can alter the structure of die soil through their effects on soil disturbance and mixing and on organic matter (OM) accumulation and mineralization. The objective of this study was to determine the changes in soil water-stable aggregation induced by 4 yr of different rotation and tillage practices on a Kamouraska clay at La Pocatière, Quebec. The influence of soil water content (WC) at time of sampling and of different biological and biochemical properties on soil aggregation was also examined. Two rotations (continuous barley (Hordeum vulgare L.) vs. a 2-yr barley–red clover (Trifolium pratense L.) rotation) and three tillage treatments (moldboard plowing (MP) chisel plowing (CP) and no-tillage (NT)) were compared in a split-plot design. Measurements of the size distribution of water-stable aggregates were made on surface (0–7.5 cm) soil samples taken periodically during the 4-yr period. Rotations had no effect on soil aggregation. The mean-weight diameter (MWD) of water-stable aggregates did not vary significantly with time under the NT treatment during the study but decreased significantly under the MP and CP treatments. In the fourth growing season, MWD values in NT plots were on average 40% higher than in MP and CP plots, which were both similar. The larger values in MWD under NT were attributable to a larger proportion of aggregates > 2 mm at the expense of smaller ones (< 1 mm). The MWD data showed important temporal fluctuations, which could in part be explained by the effects of WC at time of sampling. This effect of WC on MWD was less apparent under NT, which suggested that these aggregates were less susceptible to slaking. Among different OM fractions, the proportion of organic C present as hot-water-soluble carbohydrates was best correlated with MWD. Key words: Soil management, aggregation, slaking


2013 ◽  
Vol 27 (1) ◽  
pp. 231-240 ◽  
Author(s):  
Bo Melander ◽  
Nicolas Munier-Jolain ◽  
Raphaël Charles ◽  
Judith Wirth ◽  
Jürgen Schwarz ◽  
...  

Noninversion tillage with tine- or disc-based cultivations prior to crop establishment is the most common way of reducing tillage for arable cropping systems with small grain cereals, oilseed rape, and maize in Europe. However, new regulations on pesticide use might hinder further expansion of reduced-tillage systems. European agriculture is asked to become less dependent on pesticides and promote crop protection programs based on integrated pest management (IPM) principles. Conventional noninversion tillage systems rely entirely on the availability of glyphosate products, and herbicide consumption is mostly higher compared to plow-based cropping systems. Annual grass weeds and catchweed bedstraw often constitute the principal weed problems in noninversion tillage systems, and crop rotations concurrently have very high proportions of winter cereals. There is a need to redesign cropping systems to allow for more diversification of the crop rotations to combat these weed problems with less herbicide input. Cover crops, stubble management strategies, and tactics that strengthen crop growth relative to weed growth are also seen as important components in future IPM systems, but their impact in noninversion tillage systems needs validation. Direct mechanical weed control methods based on rotating weeding devices such as rotary hoes could become useful in reduced-tillage systems where more crop residues and less workable soils are more prevalent, but further development is needed for effective application. Owing to the frequent use of glyphosate in reduced-tillage systems, perennial weeds are not particularly problematic. However, results from organic cropping systems clearly reveal that desisting from glyphosate use inevitably leads to more problems with perennials, which need to be addressed in future research.


2001 ◽  
Vol 91 (6) ◽  
pp. 534-545 ◽  
Author(s):  
Walber L. Gavassoni ◽  
Gregory L. Tylka ◽  
Gary P. Munkvold

The dynamics of Heterodera glycines spatial patterns were studied under different tillage systems in two naturally infested soybean fields in Iowa from 1994 to 1997. At each location, there were four different tillage treatments (conventional tillage, reduced tillage, ridge tillage, and no tillage). Soil samples were taken from 98 contiguous quadrats (5.2 m2) per plot in the fall of 1994, before any tillage was performed, and in the spring of the following 3 years shortly after planting. Cysts were extracted from soil samples by elutriation and counted, and eggs were extracted from cysts and enumerated. Spatial patterns of H. glycines populations were characterized by geostatistical analysis and variance-to-mean (VM) ratios. Semivariance values were calculated for cyst and egg densities and semivariograms were constructed. In general, there was greater spatial dependence among cyst populations than egg populations. In one field with a strongly aggregated initial H. glycines population, tillage practices resulted in changes in spatial patterns of H. glycines populations, characterized by spherical-model semivariogram parameters (sill, nugget effect, and range of spatial dependence). These parameters indicated increasing aggregation over time in no tillage and ridge tillage treatments, but decreasing aggregation in reduced and conventional tillage treatments. There was an increase of 350% in sill values (maximum semivariance) for cyst populations after 3 years of no tillage, but in the conventional tillage treatment, sill values remained unchanged or decreased over time as tillage was implemented. Semivariograms for cyst and egg population densities revealed strong anisotropy (directional spatial dependence) along soybean rows, coincident with the direction of tillage practices. VM ratios for cyst counts increased each year in the no tillage and ridge tillage treatments, but decreased for 2 years in reduced tillage and conventional tillage treatments. Final VM ratios for cyst and egg counts were highest in the no tillage treatment. In a second field, with low initial aggregation of H. glycines populations, there was little measurable change in semivariogram parameters after 3 years of no tillage, but in the conventional tillage treatment, populations became less aggregated, as the range, sill, and the proportion of the sill explained by spatial dependence decreased for cyst population densities. Our results indicated that in soybean fields with initially aggregated populations of H. glycines, no tillage and ridge tillage systems promoted aggregation of the nematode population, whereas conventional and reduced tillage systems resulted in a less aggregated spatial pattern.


2010 ◽  
Vol 11 (1) ◽  
pp. 1 ◽  
Author(s):  
Salliana R. Stetina ◽  
William T. Molin ◽  
William T. Pettigrew

Cropping practices that reduce damage from reniform nematode (Rotylenchulus reniformis) and browntop millet (Urochlora ramosa) are needed for improved cotton (Gossypium hirsutum) management. The impacts of early planting dates and reduced tillage systems on these pests were investigated from 2005 to 2007. Planting dates (April 1 or May 1) and tillage systems (conventional or minimum-tillage) were evaluated on four commercial cotton cultivars in a field study at Stoneville, MS. Despite some variability in early-season root infection, reniform nematode soil populations were not affected by any of the treatments. Thus, it appears that neither the tillage practices nor the planting dates examined in this study should be recommended for inclusion in a reniform nematode management program at this time. Mid- and late-season browntop millet pressure was greater in minimum-till plots and in plots planted early. More effective season-long suppression of browntop millet was associated with the traditional planting date and conventional tillage system, so these production practices could benefit producers who need to manage this weed. Accepted for publication 9 November 2010. Published 27 December 2010.


2017 ◽  
Vol 7 ◽  
Author(s):  
Laura Antonela Iturri ◽  
Graciela Gloria Hevia ◽  
Montserrat Diaz Raviña ◽  
Daniel Eduardo Buschiazzo

Stable and labile soil organic compounds play different roles in the soil. It is a question of how far soil organic matter (SOM) fractions with different labilities vary as a function of climatic and management conditions. In order to answer this question stable (organic C -C-, total N -N-, organic P -Po-), and labile SOM fractions (total carbohydrates -CHt- and hot water soluble carbohydrates -CHw-) were measured monthly for two years in the 10-cm soil top-layer of an Entic Haplustoll, under conventional tillage (CT), vertical tillage (VT) and no-till (NT). Results showed that contents of all analyzed organic fractions were higher in NT than in VT and CT in almost all sampling dates. All organic compounds were less variable with time in NT and VT than in CT, in agreement with the smaller soil disturbance of NT and VT compared to CT. The more labile fractions varied as a function of short term changes in the climatic conditions, mainly temperature. Under soil disturbing tillage systems, the most stable fractions tended to decrease and the more labile to increase with time. This was attributed to the transformation of the more stable into the more labile fractions, possibly due to the disruption of aggregates produced by tillage that favored SOM mineralization. Po was the less variable compound, even under the most disturbing tillage conditions. The quotients C/N, CHt/C and CHw/C evolved similarly in all tillage systems, indicating that that tillage systems change the amount but not the quality of SOM.


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