scholarly journals Assessment of Soil Quality under Different Soil Management Strategies: Combined Use of Statistical Approaches to Select the Most Informative Soil Physico-Chemical Indicators

2021 ◽  
Vol 11 (11) ◽  
pp. 5099
Author(s):  
Anna Maria Stellacci ◽  
Mirko Castellini ◽  
Mariangela Diacono ◽  
Roberta Rossi ◽  
Concetta Eliana Gattullo

Assessment of soil quality under different management practices is crucial for sustainable agricultural production and natural resource use. In this study, different statistical methods (principal component analysis, PCA; stepwise discriminant analysis, SDA; partial least squares regression with VIP statistics, PLSR) were applied to identify the variables that most discriminated soil status under minimum tillage and no-tillage. Data collected in 2015 from a long-term field experiment on durum wheat (Triticum durum Desf.) were used and twenty soil indicators (chemical, physical and biological) were quantified for the upper soil layer (0–0.20 m). The long-term iteration of different management strategies affected soil quality, showing greater bulk density, relative field capacity (RFC), organic and extractable carbon contents (TOC and TEC) and exchangeable potassium under no-tillage. PCA and SDA confirmed these results and underlined also the role of available phosphorous and organic carbon fractions as variables that most discriminated the treatments investigated. PLSR, including information on plant response (grain yield and protein content), selected, as the most important variables, plant nutrients, soil physical quality indicators, pH and exchangeable cations. The research showed the effectiveness of combining variable selection methods to summarize information deriving from multivariate datasets and improving the understanding of the system investigated. The statistical approaches compared provided different results in terms of variables selected and the ranking of the selected variables. The combined use of the three methods allowed the selection of a smaller number of variables (TOC, TEC, Olsen P, water extractable nitrogen, RFC, macroporosity, air capacity), which were able to provide a clear discrimination between the treatments compared, as shown by the PCA carried out on the reduced dataset. The presence of a response variable in PLSR considerably drove the feature selection process.

Agronomy ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 650
Author(s):  
Jesús Aguilera-Huertas ◽  
Beatriz Lozano-García ◽  
Manuel González-Rosado ◽  
Luis Parras-Alcántara

The short- and medium—long-term effects of management and hillside position on soil organic carbon (SOC) changes were studied in a centenary Mediterranean rainfed olive grove. One way to measure these changes is to analyze the soil quality, as it assesses soil degradation degree and attempts to identify management practices for sustainable soil use. In this context, the SOC stratification index (SR-COS) is one of the best indicators of soil quality to assess the degradation degree from SOC content without analyzing other soil properties. The SR-SOC was calculated in soil profiles (horizon-by-horizon) to identify the best soil management practices for sustainable use. The following time periods and soil management combinations were tested: (i) in the medium‒long-term (17 years) from conventional tillage (CT) to no-tillage (NT), (ii) in the short-term (2 years) from CT to no-tillage with cover crops (NT-CC), and (iii) the effect in the short-term (from CT to NT-CC) of different topographic positions along a hillside. The results indicate that the SR-SOC increased with depth for all management practices. The SR-SOC ranged from 1.21 to 1.73 in CT0, from 1.48 to 3.01 in CT1, from 1.15 to 2.48 in CT2, from 1.22 to 2.39 in NT-CC and from 0.98 to 4.16 in NT; therefore, the soil quality from the SR-SOC index was not directly linked to the increase or loss of SOC along the soil profile. This demonstrates the time-variability of SR-SOC and that NT improves soil quality in the long-term.


Agronomy ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 291
Author(s):  
Ramón Bienes ◽  
Maria Jose Marques ◽  
Blanca Sastre ◽  
Andrés García-Díaz ◽  
Iris Esparza ◽  
...  

Long-term field trials are essential for monitoring the effects of sustainable land management strategies for adaptation and mitigation to climate change. The influence of more than thirty years of different management is analyzed on extensive crops under three tillage systems, conventional tillage (CT), minimum tillage (MT), and no-tillage (NT), and with two crop rotations, monoculture winter-wheat (Triticum aestivum L.) and wheat-vetch (Triticum aestivum L.-Vicia sativa L.), widely present in the center of Spain. The soil under NT experienced the largest change in organic carbon (SOC) sequestration, macroaggregate stability, and bulk density. In the MT and NT treatments, SOC content was still increasing after 32 years, being 26.5 and 32.2 Mg ha−1, respectively, compared to 20.8 Mg ha−1 in CT. The SOC stratification (ratio of SOC at the topsoil/SOC at the layer underneath), an indicator of soil conservation, increased with decreasing tillage intensity (2.32, 1.36, and 1.01 for NT, MT, and CT respectively). Tillage intensity affected the majority of soil parameters, except the water stable aggregates, infiltration, and porosity. The NT treatment increased available water, but only in monocropping. More water was retained at the permanent wilting point in NT treatments, which can be a disadvantage in dry periods of these edaphoclimatic conditions.


2008 ◽  
Vol 19 (5) ◽  
pp. 516-529 ◽  
Author(s):  
R. E. Masto ◽  
P. K. Chhonkar ◽  
T. J. Purakayastha ◽  
A. K. Patra ◽  
D. Singh

Agronomy ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 300 ◽  
Author(s):  
Pradeep Wagle ◽  
Prasanna Gowda

Adoption of better management practices is crucial to lessen the impact of anthropogenic disturbances on tallgrass prairie systems that contribute heavily for livestock production in several states of the United States. This article reviews the impacts of different common management practices and disturbances (e.g., fertilization, grazing, burning) and tallgrass prairie restoration on plant growth and development, plant species composition, water and nutrient cycles, and microbial activities in tallgrass prairie. Although nitrogen (N) fertilization increases aboveground productivity of prairie systems, several factors greatly influence the range of stimulation across sites. For example, response to N fertilization was more evident on frequently or annually burnt sites (N limiting) than infrequently burnt and unburnt sites (light limiting). Frequent burning increased density of C4 grasses and decreased plant species richness and diversity, while plant diversity was maximized under infrequent burning and grazing. Grazing increased diversity and richness of native plant species by reducing aboveground biomass of dominant grasses and increasing light availability for other species. Restored prairies showed lower levels of species richness and soil quality compared to native remnants. Infrequent burning, regular grazing, and additional inputs can promote species richness and soil quality in restored prairies. However, this literature review indicated that all prairie systems might not show similar responses to treatments as the response might be influenced by another treatment, timing of treatments, and duration of treatments (i.e., short-term vs. long-term). Thus, it is necessary to examine the long-term responses of tallgrass prairie systems to main and interacting effects of combination of management practices under diverse plant community and climatic conditions for a holistic assessment.


2002 ◽  
Vol 68 (8) ◽  
pp. 4090-4094 ◽  
Author(s):  
Salvador Herrero ◽  
Marisé Borja ◽  
Juan Ferré

ABSTRACT Despite the fact that around 200 cry genes from Bacillus thuringiensis have already been cloned, only a few Cry proteins are toxic towards a given pest. A crucial step in the mode of action of Cry proteins is binding to specific sites in the midgut of susceptible insects. Binding studies in insects that have developed cross-resistance discourage the combined use of Cry proteins sharing the same binding site. If resistance management strategies are to be implemented, the arsenal of Cry proteins suitable to control a given pest may be not so vast as it might seem at first. The present study evaluates the potential of B. thuringiensis for the control of a new pest, the geranium bronze (Cacyreus marshalli Butler), a butterfly that is threatening the popularity of geraniums in Spain. Eleven of the most common Cry proteins from the three lepidopteran-active Cry families (Cry1, Cry2, and Cry9) were tested against the geranium bronze for their toxicity and binding site relationships. Using 125I-labeled Cry1A proteins we found that, of the seven most active Cry proteins, six competed for binding to the same site. For the long-term control of the geranium bronze with B. thuringiensis-based insecticides it would be advisable to combine any of the Cry proteins sharing the binding site (preferably Cry1Ab, since it is the most toxic) with those not competing for the same site. Cry1Ba would be the best choice of these proteins, since it is significantly more toxic than the others not binding to the common site.


2020 ◽  
Author(s):  
Ilka Schmoock ◽  
Deborah Linsler ◽  
Mignon Sandor ◽  
Rainer Georg Joergensen ◽  
Martin Potthoff

<p>Over the last decades, reduced tillage became more and more important as a suitable soil management practice. Moreover, reduced tillage is expected to promote a healthy and active soil life as a feature of sustainable agricultural. The determination of soil microbial biomass and microbial indices are suitable indicators for estimating soil quality. This study follows a regional approach and focusses at four different countries with varying environmental conditions at long-term experimental field-sites (LTE´s) across Europe. Soil microbial biomass carbon (SMB-C), the metabolic quotient (<em>q</em>CO<sub>2</sub>) and the ratio of SMB-C to soil organic carbon (SOC) were measured as microbial properties.</p><p>Our contribution to the ongoing discussion of the effectiveness of non-conventional tillage systems is (i) the comparison between conventional ploughing (CT) and minimum tillage (MT), (ii) the comparison of inversion vs. not inversion tillage at the same working depth, (iii) the comparison of ploughing vs. no-tillage (NT), (iv) the comparison between reduced tillage systems with each other (MT vs. NT).</p><p>We found a significant difference of SMB-C for CT and MT between 0 and 10 cm in Germany and Sweden, but no difference between tillage treatments for the sampled soil profile (0-30 cm). We highlight that tillage changed the vertical distribution of SMB-C, showing similar values among soil depths under CT and a depth gradient with decreasing values for MT.</p><p>The comparison of inversion vs. not inversion tillage at the same working depth in Romania showed no differences between CT and MT at all. This suggests that humus-rich soils seem to be more resistant to tillage-related disturbances. The working depth might have a greater impact for both, inversion and non-inversion tillage than the type of the tillage system itself.</p><p>For the comparison of CT and NT, we used the field-sites in Spain and Sweden. In Spain, NT was clearly of advantage for microbial biomass and activity, compared to CT. This was true for the whole sampled soil profile (0-30 cm) whereas in Sweden differences could only be detected between SMB-C levels in two soil depths. Our results indicate that the effect of tillage seems to be smaller in cold-temperate areas.</p><p>Comparing MT and NT in Sweden, we found no difference in SMB-C between these two forms of conservation tillage, neither in the first centimeters, nor in the whole sampled profile. Consequently, minimum tillage seems to be an alternative in cold and moist regions if no-tillage is not possible to apply without reducing soil quality or crop yields.</p><p>We conclude that even if minimum and no-tillage are generally beneficial for microorganisms, there is a big variance between the different forms of reduced tillage systems. Thus, statements cannot be made across different soils and machine types, but have to be made on a regional scale.</p><p> </p>


Soil Research ◽  
2008 ◽  
Vol 46 (4) ◽  
pp. 368 ◽  
Author(s):  
K. L. Sharma ◽  
J. Kusuma Grace ◽  
Uttam Kumar Mandal ◽  
Pravin N. Gajbhiye ◽  
K. Srinivas ◽  
...  

Alfisol soils of rainfed semi-arid tropics (SAT) are degrading due to several physical, chemical, and biological constraints. Appropriate soil-nutrient management practices may help to check further soil degradation. A long-term experiment comprising tillage and conjunctive nutrient use treatments under a sorghum (Sorghum bicolor (L.) Moench)–mung bean (Vigna radiata (L.) Wilkzec) system was conducted during 1998–05 on SAT Alfisols (Typic Haplustalf) at the Central Research Institute for Dryland Agriculture, Hyderabad. The study evaluated soil and nutrient management treatments for their long-term influence on soil quality using key indicators and soil quality indices (SQI). Of the 21 soil quality parameters considered for study, easily oxidisable N (KMnO4 oxidisable-N), DTPA extractable Zn and Cu, microbial biomass carbon (MBC), mean weight diameter (MWD) of soil aggregates, and hydraulic conductivity (HC) played a major role in influencing the soil quality and were designated as the key indicators of ‘soil quality’ for this system. The SQI obtained by the integration of key indicators varied from 0.66 (unamended control) to 0.83 (4 Mg compost + 20 kg N as urea) under conventional tillage (CT), and from 0.66 (control) to 0.89 (4 Mg compost + 2 Mg gliricidia loppings) under reduced tillage (RT). Tillage did not influence the SQI, whereas the conjunctive nutrient-use treatments had a significant effect. On an average, under both CT and RT, the sole organic treatment improved the soil quality by 31.8% over the control. The conjunctive nutrient-use treatments improved soil quality by 24.2–27.2%, and the sole inorganic treatment by 18.2% over the control. Statistically, the treatments improved soil quality in the following order: 4 Mg compost + 2 Mg gliricidia loppings > 2 Mg Gliricidia loppings + 20 kg N as urea = 4 Mg compost + 20 kg N as urea > 40 kg N as urea. The percentage contribution of the key indicators towards the SQI was: MBC (28.5%), available N (28.6%), DTPA-Zn (25.3%), DTPA-Cu (8.6%), HC (6.1%), and MWD (2.9%). The functions predicting the changes in yield and sustainability yield index with a given change in SQI were also determined.


2004 ◽  
Vol 55 (3) ◽  
pp. 279 ◽  
Author(s):  
J. Dorrough ◽  
A. Yen ◽  
V. Turner ◽  
S. G. Clark ◽  
J. Crosthwaite ◽  
...  

There is an increasing interest in the development of livestock grazing management strategies that achieve environmental sustainability and maintain or improve the long-term production capacity of commercial grazing systems. In temperate Australia, these strategies are generally focussed on reducing perennial pasture decline, soil loss, acidity, and salinity. An additional challenge facing land managers and researchers is developing grazing strategies that also maintain and enhance local and regional biodiversity. However, few studies have assessed the compatibility of management practices for maintaining long-term productivity and biodiversity conservation. We still have only a very basic understanding of the effects of different grazing strategies and pasture management on biodiversity and this is a major impediment to the development of appropriate and compatible best management practice. We argue that although there is an increasing desire to find management strategies that protect and enhance biodiversity without hindering long-term agricultural production, in many cases this may not be possible. Current knowledge suggests that compatibility is most likely to be achieved using low-input systems in low productivity (fragile) landscapes, whereas in highly productive (robust) landscapes there is less opportunity for integration of productive land-use and biodiversity conservation. There is an urgent need for improved communication and collaboration between agronomic and ecological researchers and research agencies to ensure that future programs consider sustainability in terms of biodiversity as well as pasture and livestock productivity and soil and water health.


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