Changes in pore structure in a no-till chronosequence of silt loam soils, southern Ontario

1999 ◽  
Vol 79 (1) ◽  
pp. 149-160 ◽  
Author(s):  
A. J. VandenBygaart ◽  
R. Protz ◽  
A. D. Tomlin

Many research studies have dealt with the influences of minimum or no-till soil management practices on the major physical, chemical, biological and morphological properties in the soil profile. However little work has been done on the assessment of the rates of changes in pore properties as management practices are converted from conventional to no-till (NT) methods. Short-term changes in soil micromorphology attributed to conversion to no-till from conventionally tilled management are evaluated in this paper. As the number of years in no-till increased there was a decrease in the number pores of 30- to 100-µm diameter in the no-till soils. However, pores from 100- to 500-µm diameter increased in number only after 4 yr of NT. The pores of this size are important for water storage, transmission and root development. The decline in the number of these pores after no-till initiation followed by the increase after 4 yr may explain why crop yields tend to be lower only after the first few years after implementing no-till. The 100- to 500-µm diameter pores may be crucial for the proper development of roots in wheat and corn. The no-till soils had greater numbers of horizontally oriented elongated macropores in the top 5 to 15 cm of the soil profile due to the lack of tillage and annual freeze-thaw processes. These pores may inhibit proper drainage and root penetration. Rounded macropores increased with the number of years the soil was in no-till as these pores were maintained each year due to the lack of tillage and greater faunal activity in the no-till soils. Key words: Micromorphology, image analysis, earthworms, no-till, soil structure

Weed Science ◽  
2009 ◽  
Vol 57 (4) ◽  
pp. 417-426 ◽  
Author(s):  
Vince M. Davis ◽  
Kevin D. Gibson ◽  
Thomas T. Bauman ◽  
Stephen C. Weller ◽  
William G. Johnson

Horseweed is an increasingly common and problematic weed in no-till soybean production in the eastern cornbelt due to the frequent occurrence of biotypes resistant to glyphosate. The objective of this study was to determine the influence of crop rotation, winter wheat cover crops (WWCC), residual non-glyphosate herbicides, and preplant application timing on the population dynamics of glyphosate-resistant (GR) horseweed and crop yield. A field study was conducted from 2003 to 2007 in a no-till field located at a site that contained a moderate infestation of GR horseweed (approximately 1 plant m−2). The experiment was a split-plot design with crop rotation (soybean–corn or soybean–soybean) as main plots and management systems as subplots. Management systems were evaluated by quantifying in-field horseweed plant density, seedbank density, and crop yield. Horseweed densities were collected at the time of postemergence applications, 1 mo after postemergence (MAP) applications, and at the time of crop harvest or 4 MAP. Viable seedbank densities were also evaluated from soil samples collected in the fall following seed rain. Soybean–corn crop rotation reduced in-field and seedbank horseweed densities vs. continuous soybean in the third and fourth yr of this experiment. Preplant herbicides applied in the spring were more effective at reducing horseweed plant densities than when applied in the previous fall. Spring-applied, residual herbicide systems were the most effective at reducing season-long in-field horseweed densities and protecting crop yields since the growth habit of horseweed in this region is primarily as a summer annual. Management systems also influenced the GR and glyphosate-susceptible (GS) biotype population structure after 4 yr of management. The most dramatic shift was from the initial GR : GS ratio of 3 : 1 to a ratio of 1 : 6 after 4 yr of residual preplant herbicide use followed by non-glyphosate postemergence herbicides.


Agronomy ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 539 ◽  
Author(s):  
R. Michael Lehman ◽  
Shannon L. Osborne ◽  
Kimberly McGraw

Linking agricultural management tactics to quantifiable changes in soil health-related properties is a key objective for increasing adoption of the most favorable management practices. We used two long-term, no-till cropping studies to illustrate the variable patterns of response of soil structure indices and microbial activity to additional management tactics, including crop rotational diversity, residue management and cover cropping. We found that observable effects of management tactics on soil properties were often dependent on the current crop phase sampled, even though the treatments were well-established. In some cases, a single additional management tactic produced a response, two tactics each produced a response and sometimes there were interactions between tactics. However, importantly, we never observed a negative effect for any of the response variables when stacking soil health building practices in no-till cropping systems. The collective results from the two field studies illustrate that soil health improvements with stacking management tactics are not always simply additive and are affected by temporal relationships inherent to the treatments. We conclude that the implementation of multiple positive management tactics increases the likelihood that improvements in soil properties can be documented with one or more of the proxy measures for soil health.


Agronomy ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 2334
Author(s):  
Heather L. Tyler

Conservation management practices can improve soil health while minimizing deleterious effects of agriculture on the environment. However, adoption of these practices, particularly cover crops, is not widespread, as they often reduce crop yields compared to traditional management practices. The purpose of the current study was to determine if a two-species cover crop treatment of rye (Secale cereale L.) and crimson clover (Trifolium incarnatum L.) could increase soil health parameters and maximize soybean (Glycine max L.) yield greater than rye only in tilled and no-till Mississippi field soils. Enhanced microbial biomass and organic matter input from cover crops increased the activities of β-glucosidase, cellobiohydrolase, fluorescein diacetate hydrolysis, N-acetylglucosaminidase, and phosphatase in surface soils. Rye plus clover tended to elicit higher activities than rye only in no-till plots. Both cover crop treatments inhibited soybean yield in tilled plots by 11–25%. These results indicate that tillage exacerbates yield inhibition by cover crops in soybean and that double-species cover crop treatments were more consistent in increasing activities linked to nutrient cycling. Further study examining different combinations of cover crops in no-till systems is necessary to gain a better understanding of how they can be implemented to enhance soil health while maximizing crop yield.


1987 ◽  
Vol 67 (4) ◽  
pp. 919-930 ◽  
Author(s):  
L. G. WETTER ◽  
G. R. WEBSTER ◽  
J. LICKACZ

The effect of subsoiling and liming on a Dark Brown Solodized Solonetz was investigated by measuring changes in physicochemical status, root penetration, soil moisture status, and crop yields. Major differences were due to subsoiling. The pH of the Ap was increased from 5.7 to 7.0 following liming but to greater than 8.0 following subsoiling. Subsoiling elevated calcium salts from depth thus improving subsurface soil structure; SAR values of the Bnt horizon decreased from approximately 12 to less than 7; moisture status and root penetration were increased at depth. Average yearly yield of wheat was increased by 0.9 Mg ha−1 following subsoiling. The addition of lime in combination with subsoiling did not improve physicochemical properties, moisture status, or crop yields as compared to subsoiling alone. Subsoiling increased the clay content of the Ap from 16 to 27%, this elevation of clay increased the crust strength of the Ap horizon and hence the potential for surface crusting. Key words: Solonetzic, amelioration, subsoiling, lime


Agronomy ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 582
Author(s):  
Jerónimo Salinas ◽  
David Meca ◽  
Fernando del Moral

The short-term responses of soil quality indicators are important for assessing the effects of new management practices and addressing threats to crop yields in greenhouses. The aim of this study was to assess, during three consecutive cropping seasons, the effect of a sustainable management package (CRTMP)—which includes the on-site reuse of greenhouse crop residues and tillage—in comparison with conventional management, based on fertigation only (CMP), on certain biochemical soil quality indicators and crop yields. CRTMP significantly increased (p < 0.05) the values of total organic carbon (TOC), particulate organic carbon (POC), light fraction (LF), water soluble organic carbon (WSOC), and dehydrogenase (DH) and β-glucosidase (GL) activities at a depth of 0–15 cm, as well as the mean concentration of nitrates in the soil solution. In addition, a significant Pearson’s correlation (p < 0.01) found between the indicators suggested a balanced improvement of soil biological activity and nutritional soil state. Nonetheless, the significant (p < 0.05) increases in the mean concentration of chlorides in the soil solution and electrical conductivity (p < 0.05) increased the risk of salinization, which may have affected the concentration of nitrates in the petiole sap and total production in CRTMP, which were significantly lower than in CMP. Nevertheless, the proportion of premium product was significantly higher in CRTMP, while the proportion of non-commercial production decreased.


2010 ◽  
Vol 90 (3) ◽  
pp. 429-440 ◽  
Author(s):  
J. Fan ◽  
M. Hao ◽  
S S Malhi

Nitrate (NO3-) leaching and water contamination have become a worldwide concern. In this review, some examples are presented to show the extent and magnitude of NO3- accumulation in the soil profiles and its potential effects on contamination of ground water and surface water under dryland farming in northern China. Climatic and management factors affecting NO3- leaching are also discussed. In northern China, rainfall is relatively sparse, but the high intensity of precipitation and porous soils play an important role in the accumulation of NO3N in soil and its subsequent leaching in the soil profile. There is a risk of nitrate accumulation and leaching when high rates of fertilizer N are applied to improve crop yields, and it becomes even worse when conventional land use is changed from cereal crops to vegetable crops and fruit orchards. Under such conditions, shallow ground water might be polluted by NO3-. This suggests that more attention should be paid to prevent this problem by using best management practices, especially by controlling the amount of N fertilizer input, balanced fertilization, split N application, inclusion of crops with deep taproots in the rotation and minimizing summer fallow (especially tilled) frequency. Key words: Accumulation, contamination, dryland farming, ground water, leaching, nitrate, northern China


2019 ◽  
Vol 2 (4) ◽  
pp. 267-275
Author(s):  
Sung Suk Kim ◽  
Jacob Donald Tan ◽  
Rita Juliana ◽  
John Tampil Purba

This study aims to explore the financial management practices ofsmall-and-medium-enterprises (SMEs) in the Greater Jakarta (Jabodetabek). We investigate into 3 SME cases by conducting the semi-structured interviews with the owner-managers and using direct observations to know the practices of financial management of SMEs. Through the research, we have found six propositions related to the practice of short-term financial management. They apply bootstraps to ensure availability of working capital. They set aside cash reserves from retained earnings and minimize loans from financial institutions. They have the computerized system to track receivables facilitating working capital needs. They keep theirinventory control efficient to manage working capital. They screen customers using transactional records and reputations to minimize the risk of bad debts.


1993 ◽  
Vol 28 (3-5) ◽  
pp. 691-700 ◽  
Author(s):  
J. P. Craig ◽  
R. R. Weil

In December, 1987, the states in the Chesapeake Bay region, along with the federal government, signed an agreement which called for a 40% reduction in nitrogen and phosphorus loadings to the Bay by the year 2000. To accomplish this goal, major reductions in nutrient loadings associated with agricultural management practices were deemed necessary. The objective of this study was to determine if reducing fertilizer inputs to the NT system would result in a reduction in nitrogen contamination of groundwater. In this study, groundwater, soil, and percolate samples were collected from two cropping systems. The first system was a conventional no-till (NT) grain production system with a two-year rotation of corn/winter wheat/double crop soybean. The second system, denoted low-input sustainable agriculture (LISA), produced the same crops using a winter legume and relay-cropped soybeans into standing wheat to reduce nitrogen and herbicide inputs. Nitrate-nitrogen concentrations in groundwater were significantly lower under the LISA system. Over 80% of the NT groundwater samples had NO3-N concentrations greater than 10 mgl-1, compared to only 4% for the LISA cropping system. Significantly lower soil mineral N to a depth of 180 cm was also observed. The NT soil had nearly twice as much mineral N present in the 90-180 cm portion than the LISA cropping system.


Soil Research ◽  
2019 ◽  
Vol 57 (2) ◽  
pp. 200 ◽  
Author(s):  
J. Somasundaram ◽  
M. Salikram ◽  
N. K. Sinha ◽  
M. Mohanty ◽  
R. S. Chaudhary ◽  
...  

Conservation agriculture (CA) including reduced or no-tillage and crop residue retention, is known to be a self–sustainable system as well as an alternative to residue burning. The present study evaluated the effect of reduced tillage coupled with residue retention under different cropping systems on soil properties and crop yields in a Vertisol of a semiarid region of central India. Two tillage systems – conventional tillage (CT) with residue removed, and reduced tillage (RT) with residue retained – and six major cropping systems of this region were examined after 3 years of experimentation. Results demonstrated that soil moisture content, mean weight diameter, percent water stable aggregates (&gt;0.25mm) for the 0–15cm soil layer were significantly (Pmoderately labile&gt;less labile. At the 0–15cm depth, the contributions of moderately labile, less labile and non-labile C fractions to total organic C were 39.3%, 10.3% and 50.4% respectively in RT and corresponding values for CT were 38.9%, 11.7% and 49.4%. Significant differences in different C fractions were observed between RT and CT. Soil microbial biomass C concentration was significantly higher in RT than CT at 0–15cm depth. The maize–chickpea cropping system had significantly (P–1 followed by soybean+pigeon pea (2:1) intercropping (3.50 t ha–1) and soybean–wheat cropping systems (2.97 t ha–1). Thus, CA practices could be sustainable management practices for improving soil health and crop yields of rainfed Vertisols in these semiarid regions.


2021 ◽  
Vol 13 (13) ◽  
pp. 7007
Author(s):  
Habtamu Nebere ◽  
Degefa Tolossa ◽  
Amare Bantider

In Ethiopia, the practice of land management started three decades ago in order to address the problem of land degradation and to further boost agricultural production. However, the impact of land management practices in curbing land degradation problems and improving the productivity of the agricultural sector is insignificant. Various empirical works have previously identified the determinants of the adoption rate of land management practices. However, the sustainability of land management practices after adoption, and the various factors that control the sustainability of implemented land management practices, are not well addressed. This study analyzed the factors affecting the sustainability of land management practices after implementation in Mecha Woreda, northwestern Ethiopia. The study used 378 sample respondents, selected by a systematic random sampling technique. Binary logistic regression was used to analyze the quantitative data, while the qualitative data were qualitatively and concurrently analyzed with the quantitative data. The sustained supply of fodder from the implemented land management practices, as well as improved cattle breed, increases the sustainability of the implemented land management practices. While lack of agreement in the community, lack of enforcing community bylaws, open cattle grazing, lack of benefits of implemented land management practices, acting as barrier for farming practices, poor participation of household heads during planning and decision-making processes, as well as the lack of short-term benefits, reduce the sustainability of the implemented land management practices. Thus, it is better to allow for the full participation of household heads in planning and decision-making processes to bring practical and visible results in land management practices. In addition, recognizing short-term benefits to compensate the land lost in constructing land management structures must be the strategy in land management practices. Finally, reducing the number of cattle and practicing stall feeding is helpful both for the sustainability of land management practices and the productivity of cattle. In line with this, fast-growing fodder grass species have to be introduced for household heads to grow on land management structures and communal grazing fields for stall feeding.


Sign in / Sign up

Export Citation Format

Share Document