Soil Management Treatments Research Articles

Soil Nutrient Management Practices Influence the Carotenoid Content and Profile of Orange Fleshed Sweet Potato Variety (UMUSPO 3)

Food bio fortification holds a lot of promise for the alleviation of hidden hunger. The appropriate soil nutrient management methods that will maximize the pro vitamin A content of bio fortified Orange fleshed sweet potatoes bio fortified was evaluated in the present research. The carotenoid content and profile of OFSP variety grown on soils given five different nutrient managements were compared. The soil management treatments given were: Poultry manure at 10 x 103 kg /ha (VB1); Poultry manure at 5 x 103 kg/ha;( VB2): Poultry manure at 2.5 x 103 kg/ha + NPK at 200 kg/ha + Agrolyser at 2.7 kg/ha, (VB3) Agrolyser at 2.7 kg/ha + NPK at 200 kg/ha; (VB4) Poultry manure at 5.0 x 103 kg/ha + NPK at 200 kg/ha, (VB5) NPK 15:15:15 at 400 kg/ha. Carotenoids were extracted from the potato samples and analyzed using High performance Liquid Chromatography (HPLC). The best treatment that promoted high pro vitamin A carotenoid content was soil treatment with Poultry manure (5x 103 kg/ha+ NPK (200kg/ha). This soil treatment led to the highest contents of α-carotene (6.14μg/g); 13-cis-β-carotene (12.36μg/g); All-trans-β-carotene (87.89μg/g) and 9-cis-β-carotene (2.99μg/g). The best soil management treatment for the highest yield of β-cryptoxanthin (7.95μg/g) was poultry manure at 2.5kg/ha +NPK at 200kg/ha.

A new integrated approach for management of soil threats in the vineyard ecosystem

The relevance of soil threats at affecting yield and grape composition is currently largely neglected as compared to the attention devoted to canopy factors. In this paper, we provide a new soil assessment procedure that, with the help of a web based new decision tool (DT), allows to (i) rate potential soil threats through a computer engine that processes a detailed check list of vineyard and site specific characteristics, (ii) identify which potential threats are valid on the basis of physical and/or analytical vineyard assessment, (iii) propose through a decision engine best soil mitigation solutions according to real threats and (iv) evaluate soil’s threats changes after the mitigation solution’s implementation. All gathered data were also used for a Strengths, Weaknesses, Opportunities, and Threats (SWOT) analysis and estimation of possible ecosystem services. Traditional (e.g combinations of tillage and native grassing) vs innovative soil management (SM) treatments were evaluated over three years (2017–2019) in nine test vineyards sited in the Parma and Piacenza provinces (Northern Italy).As expected, fraction of real-to-potential threat increased from 22% to 79% with increasing potential threat severity; however, potential threats classified as very likely (red color) had a 55% conversion rate into real threat, suggesting that summer drought and erosion threat assessment require more deepening. Overall, mitigation SM solutions consisting of a sown cover crop in mid-rows with the slashed sward either left on site and piled beneath the row or in temporary winter grassing followed by green manuring improved vine performances as compared to tillage and native grassing. SWOT analysis unleashed that the same SM solutions are well-perceived by growers who are still reluctant to incur additional costs for their implementation. A total ES benefit of 1454 € ha−1, with soil erosion containment accounting for 700 € ha−1, was estimated. To our knowledge, this is the first attempt to provide grape growers with a tool allowing objective assessment of real soil threats. Albeit grapevine is taken as use case in this study, the same protocol is valuable in any orchard ecosystem organized in single rows separated by a mid row alley.

Effect of Long-Term Use of Tillage, Crop Residue and N Application on Phosphorus Fractions in Soil under Sorghum (Sorghum vulgare) (L.)-castor System (Ricinus Communis) in Rainfed Alfisol Soils

ABSTRACT A long-term field experiment was conducted at Hayathnagar Research Farm (HRF) of ICAR-Central Research Institute of Dryland Agriculture with the objectives to assess the effect of soil management practices viz tillage, residue application and N levels on soil phosphorus fractions, their interrelationships among themselves, impact on soil P availability pool, crop yields and P uptake. The results of the study clearly indicated that the long-term use of tillage, application of residues and N levels had a significant effect on all the P fractions in soils, except that water-soluble phosphorus (WSP) was not significantly influenced by the tillage practices. The Tillage x Residue x Nitrogen (T × R × N) significantly influenced the reductant soluble phosphorus (RSP) and total phosphorus (TP); however, the remaining P fractions were not influenced significantly. Among the combination of soil management treatments, conventional tillage (CT)+ Gliricidia loppings @ 2 tha−1 (GL) + N level @ 90 kg ha−1 (N90) (CTGLN90) gave the highest sorghum grain yield (1432 kg ha−1) and P uptake (14.20 kg P ha−1). Among the treatment combinations, the order of superiority of treatments in terms of castor yield and P uptake was: CT+ sorghum stover @ 2t ha−1 (SS) + N90 (CTSSN90) (1788 kg ha−1, 11.94 kg P ha−1) > Minimum Tillage (MT) + sorghum stove @2 t ha−1 (SS) + N level @ 90 kg ha−1 (N90) (MTSSN90) (1761 kg ha−1, 14.24 kg P ha−1), respectively. Significant coefficients of multiple determination obtained from regression equations developed between sorghum crop yield and P fractions (R2 = 0.726, p = .05) and sorghum P uptake and P fractions (R2 = 0.620, p = .05) highlighted the importance of these fractions in influencing the crop yield and P uptake. Similarly, castor yield (R2 = 0.748, p = .05) and P uptake (R2 = 0.783) were significantly influenced by the P fractions. The results of the present study will be useful in understanding the effect of soil management practices on the status of P fractions and their contribution toward P uptake and crop yields.

Carabid beetles (Coleoptera: Carabidae) differentially respond to soil management practices in feed and forage systems in transition to organic management

AbstractWe conducted a 3-yr cropping systems experiment in central Pennsylvania, USA, to determine the effects of initial cover crop species, tillage and resulting environmental variables on the activity–density (A–D), species richness, community composition and guild composition of carabid beetles (Carabidae: Coleoptera) during the transition from conventional to organic production. We compared four systems in a factorial combination of a mixed perennial sod (timothy, Phleum pratense L.) and legumes (red clover, Trifolium pratense L.) or annual cereal grain (cereal rye, Secale cereale L.) followed by a legume (hairy vetch, Vicia villosa Roth) as initial cover crops, and soil management using full tillage (moldboard plow) or reduced tillage (chisel plow) implemented in soybeans followed by maize in the subsequent year. The experiment was established twice, first in autumn 2003 (S1) and again in autumn 2004 (S2) in an adjacent field, in a randomized complete-block design with four replicates in each Start. We collected a total of 2181 adult carabid beetles. Approximately 65% of the carabid beetles collected were from six species. Indicator Species Analysis showed that several carabid species were indicative of treatment, e.g., Poecilus chalcites was a strong indicator for treatments with an initial cereal rye cover crop. Eleven environmental variables explained variation in carabid A–D, richness and the A–D of species categorized by size class and dominant trophic behavior, respectively, but varied in significance and direction among guilds. Soil moisture was a significant effect for total carabid A–D in both S1 and S2. Redundancy analyses revealed some similar and some idiosyncratic responses among informative species for the cover crop×tillage treatments through the 3-yr rotation. The most consistent factors that distinguished species assemblages among years and treatments were the number and intensity of soil disturbances and perennial weed density. The consistent occurrence of soil disturbance indicators in multivariate analyses suggests that future studies that aim to compare the effects of nominal soil management treatments on carabid beetles and other soil-associated arthropods should quantify frequency and intensity of disturbance associated with crop management practices.

Integration of maize between rice and wheat with soil and nutrient management to improve productivity of rice-wheat cropping system in Bangladesh

The necessity of more food production from limited land enforced cropping intensification over-exploring the natural resources in Bangladesh. This field experiment was initiated to achieve improve and sustainable productivity of an intensive wheat-maize-rice cropping system with improved management of natural resources. Four levels of nutrient managements were tested under four soil management treatments starting with wheat crop sown in November 2009 and ending with the harvest of 8th wheat crop in the system during March 2017. Yield and yield contributing characters of component crops and soil properties were studied following standard methods. Soil management treatment of rice straw mulch application in reduced till-bed or well-till flat soil upon wheat sowing was equally effective in conserving soil moisture, enhancing wheat root development, reducing weed growth and thereby positively influenced spikes/m2 and finally wheat yield. Similarly, wheat straw mulch application contributed to ears/m2 and grain yield of maize. Nutrient levels of recommended fertilizers plus 5.0 t/ha cowdung resulted in yield improvement of wheat and maize throughout the years. However, neither nutrient management nor soil management alone but the combination of recommended fertilizers with 5 t/ha cowdung couple with rice straw mulching in wheat and wheat straw mulching in maize resulted in maximum wheat and maize yield over the years. Rice yield was similar for different treatment combinations until the 4th cropping cycle and thereafter rice yield was also improved by the residual effect of straw mulches. Crop residue mulching along with addition of organic and inorganic fertilizers was found to be a promising soil management technology for achieving sustainable increased productivity of wheat-maize-rice system.
 Bangladesh J. Agril. Res. 44(2): 203-221, June 2019

Effect of reduction of aggregate size on the priming effect in a Mollisol under different soil managements

SummaryThe priming effect (PE) is influenced by the amount and quality of soil organic carbon (SOC) held in different soil aggregates sizes. We examined the PE in Mollisols managed for >30 years as a grassland, farmland and bare fallow with 51, 32 and 27 g of SOC kg−1 soil, respectively, in a 60‐day incubation. Grassland soil contained 75% of aggregates in the macro size fractions >0.25 mm compared to <32% in farmland and bare fallow. Farmland and bare fallow soils contained proportionately more micro size fractions. The effect of aggregate size on the PE was assessed by comparing soils with intact aggregates to those where macroaggregates were reduced to microaggregate size fractions. In the grassland soil, cumulative CO2 mineralization increased by 20% in the reduced aggregate‐size treatment with no effect on farmland or bare fallow soils. Substrate additions to examine the PE included 13C‐glucose and 13C‐alanine (0.4 g C kg−1 dry soil), and inorganic N (2 mg N kg−1 dry soil). The PE was in the order glucose > alanine > (NH4)2SO4 and was most intense at day 3 of the incubation. Aggregate‐size reduction did not affect the PE within soil management treatments regardless of substrate addition. Most of the CO2 produced was derived from SOC rather than substrate addition and peaked at day 3. There was an interaction between microbial biomass C and dissolved organic C on the PE in the grassland soil only. The results suggested that the PE is an intrinsic characteristic of soils that are more affected by available C than the SOC in different aggregate fractions.Highlights The priming effect from added C substrates was examined in relation to aggregate size. Reducing macroaggregates to <0.25 mm increased CO2 production in a grassland but not agricultural Mollisol. The positive priming effect was proportionately reduced in soil dominated by macroaggregates. The priming effect is an intrinsic characteristic affected by C additions and less so by aggregate protected C.

Temporal variability of soil water content and penetration resistance under different soil management practices

This study analyzed the temporal induced variability of soil penetration resistance (PR) and soil water content (SWC) of eight soil treatments, which ranged four tillage systems (conventional tillage [CT], reduced tillage [RT], no-tillage [NT], and fallow no-tillage [FNT]), to four soil management treatments (abandoned soil [that is, control], compacted soil, CT on compacted soil [tilled], and application of super absorbent polymers [SAP] on abandoned soil). The treatments were arranged in 20 × 4 m (65.6 × 13.1 ft) plots with four replicates. The temporal variability of soil PR and SWC was determined using four measurement repetitions over time, from 2014 to 2015 (December, February, April, and June). A total of 64 soil samples (four replications × eight treatments × two soil depth layers) were collected for the analysis of the temporal variations of SWC at four different times. According to the study, soil PR and SWC were influenced by soil management and tillage systems. Also, the study indicated that PR and SWC varied over time. For different treatments, a second degree polynomial correlation between PR and soil depth was observed during all measurement times. Tillage practice on compacted soils resulted in a decrease in PR during all measurement times and in both depths. In general, for most of the investigated soil treatments, a low variability of SWC between treatments was obtained at a given measurement time. It was discovered that the effect of soil management and soil depth was significant for SWC, but the interaction between depth and management was not statistically significant for any measurement time. The effect of soil treatment and soil depth, and the interaction between them, was significant for PR at p

Diagnosing, Ameliorating, and Monitoring Soil Compaction in No‐Till Brazilian Soils

Core Ideas One‐time tillage increased soybean yield as a result of improving soil physical properties. Penetration resistance, air capacity, macroporosity, relative field capacity, and S index were the soil physical properties that best predicted soybean yield. The most sensitive soil physical properties for detecting structural related alterations were equally important for predicting soybean yield. Penetration resistance is the indicator that addresses no‐tillage soil compaction and its effect on soybean yield. Soil compaction can significantly reduce crop yield. Our objective was to identify the most sensitive soil physical property and process indicators related to crop yield using a Random Forest algorithm (RFA). This machine‐learning, decision‐making tool was used with field‐scale data from five soil management treatments designed to ameliorate compaction in no‐tillage (NT) fields. The treatments were: T1, NT for 10 yr (control); T2, NT with surface application of 3.6 Mg ha−1 of agricultural gypsum; T3, NT with subsoiling plus 1.44 Mg ha−1 of highly reactive limestone applied to a depth of 0.60 m; T4, NT planting following chisel plowing at a depth of 0.26 m; and T5, NT with subsoiling to a depth of 0.60 m plus 1.44 Mg ha−1 of surface‐applied, highly reactive limestone. Fifteen soil physical properties and processes related to growth and yield of soybean [Glycine max (L.) Merr.] were measured. Mechanical intervention, specifically subsoiling, improved soil physical properties and increased soybean yield cultivated following occasional tillage. The RFA ranked penetration resistance (PR), air capacity, macroporosity, relative field capacity, and the Dexter‐S index as the most sensitive soil physical indicators affecting soybean yield. Those indicators were also sensitive to changes in soil structure due to subsoiling. We conclude that the RFA was an effective tool for screening indicators and that those chosen can be effective for monitoring soil compaction and its effect on soybean yield. Penetration resistance may be used to guide on‐farm decision‐making regarding when and how NT soil compaction should be addressed.

The Effect of Irrigation Frequency, Phosphorus Fertigation, and Cultivar on Levels of Phenolic Compounds in Sweet Cherries

This work examined the effect of irrigation frequency and phosphorus (P) fertigation on the levels of phenolic compounds present in two sweet cherry cultivars, ‘Skeena’ and ‘Cristalina’, over three growing seasons (2012–14). Two irrigation treatments were tested: a high irrigation frequency (I1) and a low irrigation frequency (I2). Both irrigation treatments applied the same quantities of water [100% evapotranspiration (ET)], but the high irrigation frequency applied water four times daily (0300, 0900, 1500, and 2100 hr) whereas the low irrigation frequency was applied at one time (0900 hr) every second day. Three soil management treatments were investigated, including 1) an unmulched control receiving no P, 2) a 10-cm waste wood mulch receiving no P, and 3) a treatment involving annual fertigation of 20 g P/tree at full bloom as ammonium polyphosphate. It was determined that cultivar was the most important factor affecting levels of phenolic compounds in sweet cherries, with generally greater levels associated with ‘Skeena’. The effect of different irrigation and fertilization strategies showed less promising results in terms of influencing levels of phenolic compounds. Both severe and mild water stress did not show an appreciable influence on increasing levels of phenolic compounds in cherries. Furthermore, severe water stress, which occurred during 2012, was associated with the lowest annual concentration of phenolic compounds and an economically unacceptable reduction in fruit size. Phosphorus fertigation influenced cherry phosphorus status positively by increasing leaf and fruit P concentrations consistently, yet these fruit exhibited lower levels of phenolic compounds.

Effect of Soil Management Practices on the Sweeping Operation during Coffee Harvest

Core Ideas The harvest performance can be affected by plant phenological behavior, non‐uniform fruit ripening, late harvest, pests and diseases, rods vibration intensity, displacement velocity and, finally, slope. After harvesting, the approximately 10–20% of coffee cherries that fall on the ground are known as the sweeping coffee and require a gathering operation. The mechanical sweeping and gathering allow higher operational capacity (working greater areas in shorter times), thus increasing profitability and reducing operational costs, however, these machines are sensitive to oscillation and/or soil topography. In addition to this limiting factor, one of the main obstacles to mechanical picking of sweeping coffee is the subsoiling operation that consists of unpacking the soil by moving the soil surface of the coffee interlines, where the coffee berries are to be harvested later . In this context, assuming that the subsoiling operation could affect the losses during the mechanical picking of sweeping coffee, this study aimed at using the SPC tools to monitor the ability of management processes to reduce losses in the sweeping and mechanical picking of fallen coffee for four soil managements. The mechanical sweeping and picking of coffee berries are necessary to recover berries that naturally fall on the soil during the mechanical harvesting process. The soil characteristics and the materials that are collected affect these two operations; in addition, there are reports that suggest that mechanical sweeping and picking are hampered by subsoiling. In this regard, the current study evaluated losses during the mechanical sweeping and picking of coffee cultivated under four soil management treatments in Presidente Olegário, MG, Brazil. The four treatments consisted of the following soil management practices: subsoiling and crushing; subsoiling and harrowing; subsoiling followed by harrowing and crushing; and the control, with no soil management. The soil was prepared in 2014, while the coffee sweeping and picking occurred in 2015 and 2016. The experimental design followed the assumptions of statistical process control, and fifteen points were evaluated per treatment in accordance with the statistical process control guidelines. The lowest loss rates were obtained for the subsoiling and crushing soil management treatment, whereas harrowing after subsoiling led to the highest losses and the lowest process quality.

Effect of soil management strategies on the characteristics of the grapevine root system in irrigated vineyards under semi-arid conditions

Background and Aims Several studies have shown that cover crops restrict the development of shallow grapevine roots and reduce vigour and yield in the vineyard. The objective of this study was to evaluate the long‐term effects, after 8 years, of four soil management practices on grapevine root development and on yield in irrigated vineyards under semi‐arid conditions. Methods and Results Four soil management treatments were established in the inter‐row: no‐tillage with herbicide application (herbicide treatment), tillage (tillage treatment), no‐tillage with self‐seeding annual grass cover crop [self‐seeding annual grass cover crop treatment (AGT)] and tillage with annual cereal seeding [annual cereal treatment (CT)]. The density of lignified grapevine roots was determined using the trench method during grapevine dormancy. The treatments CT and AGT increased grapevine root density as compared to bare soil treatments. In addition, annual cereal treatment and AGT reduced vigour and yield but only in extremely dry years. Conclusions Unlike previous studies on cover crops, our results show that annual cover crops enhance grapevine root growth both under the row and in the inter‐row as compared to bare soil management. The increased grapevine root growth was mainly due to the proliferation of fine roots (diameter less than or equal to 1 mm), while yield reduction was mainly due to fewer berries per bunch. Significance of the Study This study proves that coupling cover crop management with the grapevine growth cycle under irrigated semi‐arid conditions can improve vineyard sustainability with an average yield reduction of less than 15%. To achieve this goal, cover crop competition must be avoided during the stages of the grapevine most sensitive to water deficit or during periods of low water availability. These are mainly during fruitset and ripening.

Cross-laboratory comparison of fluorimetric microplate and colorimetric bench-scale soil enzyme assays

There has been growing interest in fluorescence-based microplate methods to measure enzyme activities due to the sensitivity of fluorimetric detection and the potential for simultaneous and rapid assaying of multiple enzyme activities in the same soil suspension. However, micro-scale methods could introduce considerable operator error such as: 1) the requirement to put soil samples into a suspension; 2) the very small amounts of soil placed in each microplate well; 3) pipetting error because μL volumes are required; and 4) the need for standard curve calibration with every sample to account for quenching. For valid data comparison and interpretation, there is clearly a need to have a strict and agreed-upon enzyme assay protocol to standardize the microplate-based method. Therefore, the objectives were to: 1) determine the reproducibility and comparability of the standard p-nitrophenol bench-scale and 4-methylumbelliferone microplate enzyme assays measured by five laboratories for β-glucosidase (EC 3.2.1.21) and acid phosphomonoesterase (EC 3.1.3.2) on the same soil samples; and 2) determine the degree and the sources of variability associated with the assays within and among the laboratories. The results showed that overall variability was highest for replication on the microplate (n = 4), whereas suspension replication had low CVs. This suggests an important source of variation is from pipetting not variability from soil suspensions. A major effort was made to control for methodological differences by using air-dried soils (therefore more stable over varying storage periods) and operator consistency for each task across the labs (e.g. preheated reagents, microplate reader sensitivity set to the highest standard, readings taken within an hour of reaction termination, and controls for substrate autohydrolysis). As a result, the differences among labs were much smaller than differences due to soil type for the microplate method, indicating operator error can be minimized by following the same strict protocol. At the molar level, enzyme activity rates measured across the five labs were not the same between bench and MUF microplate methods (although they were within an order of magnitude), but were quite similar in terms of ranking of soil management treatments and soil types (Table 2). Correlations between bench and microplate assays were strong for both enzymes, although slightly stronger for acid phosphomonoesterase (r = 0.93) than β-glucosidase (r = 0.81). Additionally, for both acid phosphomonoesterase and β-glucosidase, correlation r values were mostly similar for MUF microplate and PNP bench method correlation with EL-FAME biomarkers, suggesting both methods were measuring activity originating from the same microbial groups. We conclude that different labs using the same MUF microplate protocol tested, gives reasonably similar absolute activity values, variability, and ranking of treatments (highest to lowest). We propose that the MUF microplate method described in this study be considered as a standard protocol for assaying soil enzyme activities, providing that the buffer pH for the incubation be adjusted to the optimal pH according to the enzyme of interest.

Deep Tillage and Gypsum Amendments on Fully, Deficit Irrigated, and Dryland Soybean

Core Ideas Deep tillage practices increase soybean yield.Irrigation is a recommended practice for maximizing soybean yields.As the irrigation deficit is increased the soybean seed yield decreases. A major limitation to soybean [Glycine max (L.) Merri.] yield is the availability of water for crop production; however, water available for irrigation is declining in many of the crop growing regions. The objectives of this study were to validate and/or refine current allowable deficit recommendation for evapotranspiration (ET)‐based irrigation scheduling for furrow irrigated soybean and to examine the effects of deep tillage and gypsum amendment on yields and water use efficiency (WUE). This experiment was conducted near Stuttgart, AR, across three growing seasons on a soil type described as a fine, smectitic, thermic Typic Albagualf. The soil management treatments were deep tillage, deep tillage/gypsum application, conventional tillage/gypsum application, and conventional tillage. Irrigation treatments (fully irrigated, +1 deficit, +2 deficit, and non‐irrigated), were replicated three times within each soil treatment. Increases in soybean yields above 20% (2013), 9% (2014), and above 10% (2015), were observed in the deep tillage treatments. No yield benefits were observed in the gypsum amendment treatments. The +1 deficit resulted in reduction of irrigation water used and can be used in conjunction with deep tillage to obtain similar yield responses as fully irrigated treatments. In conventional treatments reduction in yield was observed at all levels of irrigation deficit except for fully irrigated treatments, indicating that conventional soil management practices should follow Arkansas allowable deficit recommendation for ET‐based irrigation scheduling as a maximum allowable deficit to prevent yield loss.

Effect of rootstocks and soil management on growth and physiological parameters in new plantations of apple under replant conditions

Apple orchards planted in late sixties in Himanchal Pradesh and North Western Himalayan region have shown symptoms of declining productivity as these plants have completed their economic life span. Due to limited land and choice of crops for smaller micro climatic niches and incomparable economic equivalence of other fruits with apple, orchardists are compelled to replant at old apple orchard sites. Standardization of suitable agro-techniques to combat replant problem in apple for better field survival rate and productivity is required to sustain apple industry in the state. In the present study, there were 20 treatments comprising of four apple rootstocks i.e. seedling, M793, MM111 and M7 and five different soil management treatments i.e. control, soil fumigation, Plant growth promoting rhizobacteria (PGPR), biocontrol and combined soil fumigation + PGPR + Biocontrol with three replications. The pooled data over the years 2015 and 2016 revealed that M793 rootstock had the maximum growth, vigour, chlorophyll content and photosynthetic efficiency. Among the soil management treatments, the highest growth and vigour parameters, chlorophyll content and photosynthetic efficiency were recorded maximum in combined treatment. The interaction between rootstocks and treatments revealed that combinations of M793 and combined treatment resulted the maximum growth and vigour traits, chlorophyll content, rate of photosynthesis, transpiration rate, stomatal conductance, water use efficiency and minimum stomatal resistance compared to other rootstocks and treatment combinations under replant situations, which can be exploited for the management of replant problem in apple.

Root Activity and Antioxidant Enzyme Activities of Rice Cultivars under Different Iron Toxicity Mitigation Options

Iron (Fe) toxicity is a widespread environmental problem of rice growing area in many parts of the world. Amendments and genotypes can be used to mitigate the Fe toxicity. Several strategies may be adopted by higher plants to cope up with high levels of soluble Fe in their environment. A field experiment was carried out in acidic laterite soil having 400 mg kg−1 di-ethylene tri-amine-penta-acetic acid extractable Fe (DTPA-Fe) to assess the root activity and antioxidant enzyme activities of rice cultivars under different soil management options in Fe toxic soil. The treatments comprised of four cultivars (two each tolerant and susceptible) and six amendments. The amendments resulted into the increase in soil pH as compared to the control, which helps in mitigation of Fe toxicity. Tolerant cultivars recorded significantly higher rice root oxidation and Fe plaque deposition as compared to sensitive cultivars under all the soil management treatments. Cultivars also differed significantly in the amount of Fe plaque on the roots under control. Iron concentration in the roots showed a reverse trend as compared to Fe oxidation and Fe plaque for all the cultivars and soil management treatments. Under high toxic Fe level (control), due to high activity of peroxidase (POD), catalase (CAT) and superoxide dismutase (SOD) mechanisms of antioxidative defense were more active for tolerant cultivars as compared to susceptible cultivars. The effect of defense mechanism of the tolerant cultivars is manifested in yield and under control condition, higher yield were reported for tolerant cultivars as compared to susceptible. Lime application is the most effective way to overcome the Fe toxicity, which increased the yield of both the tolerant and susceptible rice cultivars. Rice roots plays important role in alleviating the Fe toxicity by oxidizing the Fe2+ and excluding its uptake. Iron resistance of the tolerant cultivars is also attributed to the comparatively high levels of POD, CAT, and SOD activities in the leaf tissues. The differential response of the cultivars to the Fe-toxicity is due to differential ability of Fe compartmentation, root oxidation power and ability of cultivars to produce antioxidative stress enzymes. The mechanisms of Fe toxicity tolerance both in plant and soil are result of combined effect of genetics of the crop plant and management interventions.

Relationships between labile soil organic carbon fractions under different soil management systems

The study of labile carbon fractions (LCF) provides an understanding of the behavior of soil organic matter (SOM) under different soil management systems and cover crops. The aim of this study was to assess the effect of different soil management systems with respect to tillage, cover crop and phosphate fertilization on the amount of the LCF of SOM. Treatments consisted of conventional tillage (CT) and no-tillage (NT) with millet as the cover crop and a no-tillage system with velvet bean at two phosphorus dosages. Soil samples were collected and analyzed for organic carbon (OC), C oxidizable by KMnO4 (C-KMnO4), particulate OC (POC), microbial biomass carbon and light SOM in the 0.0-0.05, 0.05-0.10 and 0.10-0.20 m soil layers. The Carbon Management Index (CMI) was calculated to evaluate the impacts of soil management treatments on the quality of the SOM. The different LCFs are sensitive to different soil management systems, and there are significant correlations between them. C-KMnO4 is considered the best indicator of OC carbon lability. In the soil surface layers, the CT reduced the carbon content in all of the labile fractions of the SOM. The use of phosphorus led to the accumulation of OC and carbon in the different soil fractions regardless of the tillage system or cover crop. The application of phosphate fertilizer improved the ability of the NTsystem to promote soil quality, as assessed by the CMI.

Assessment of GMean Biological Soil Quality Indices under Conservation Agriculture Practices in Rainfed Alfisol Soils

The present study was conducted in 2009-10 with the objective to monitor the effect of restorative soil management practices on biological soil quality. The experiment was initiated in 1995 in a strip-split-split plot design with three replications. Sorghum and castor were grown in two-year rotations. The procedure comprised of two tillage treatments: conventional tillage (CT) and minimum tillage (MT; main plots), three residues treatments: sorghum stover (SS), Gliricidia loppings (GL), no residue (NR; sub-plots), and two nitrogen levels 0 (N0) and 90 kg ha -1 (N90) (sub-subplots). After 15th year of the experiment, activities of the soil enzymes, microbial biomass carbon (MBC), labile carbon (LC) and organic carbon (OC) were studied. Soil management treatments significantly influenced the soil enzyme activities. Enzyme activity was significantly correlated with MBC, LC and OC. The biological soil quality has been assessed in terms of GMeanBSQI (geometric mean of biological soil quality index). From the viewpoint of GMeanBSQI, the order of superiority of soil management treatments was: MT (0.82) > CT (0.69). The performance of the residues was in the order GL (0.87) > SS (0.75) > NR (0.65). Nitrogen @ 90 kg ha -1 (0.81) proved superior to no nitrogen (N0 - 0.70). Among all the treatment combinations, MTGLN90 was found to be the most superior management option for ensuring higher GMean in rainfed Alfisol soils. The present study indicates that crop residue management under minimum tillage is of great significance in improving the biological soil quality indicators and indices. The results obtained are significant in improving biological soil quality index and crop productivity through appropriate soil management.

Chemical and physical changes in an Argisol under agrosilvopastoral system in Votuporanga, São Paulo State, Brazil

Conservation management systems that have intended to prevent wear or soil degradation have been widespread in agriculture. The study was conducted in Site Sao Luiz at Simonsen district, Votuporanga, Sao Paulo State, in order to evaluate the chemical and physical changes in an area with agrosilvopastoral system and deployed with three soil management (treatments): Full (conventional tillage, liming and application of gypsum, phosphate and potassium); intermediate (no tillage, liming and application of gypsum at surface) and basic (no tillage and surface liming). The soil was managed in July 2009 and the planting of eucalyptus was realized in January 2010, on the terraces. Between the terraces it was cropped maize intercropped with Urochloa brizantha cv. Marandu. In April 2014 it was held the disturbed and undisturbed soil sampling soil at depths of 0-0.05 and 0.05-0.20 m, collecting three sub samples per plot. A randomized complete block experimental design was used with three replications, with plots of approximately 1.0 ha. It was concluded that in the layer of 0-0.05m, the intermediate management provided increase in the levels of organic matter, Ca, P and K and the basic management provided lower levels of Ca and lower pH and basis saturation values and higher potential acidity; the complete and intermediate managements provided raising the pH in the two layers evaluated; the use of liming associated with gypsum application improves the chemical characteristics of Argisols under agrosilvopastoral systems; in the layer of 0.05-0.20 m the basic management provided lower bulk density and the complete management the largest; the different managements did not differ with respect to porosity and aggregate stability.

Effects of irrigation deprivation and ground cover (Trifolium repens) in the tree row on brown rot incidence in peach

Brown rot can lead to considerable fruit losses in peach orchards and cultural practices likely to contend this major disease have to be promoted. In order to limit peach brown rot incidence in a three-year-old mid-season maturing peach orchard of the cultivar ’Ruby Bright’, four combinations of irrigation and soil management treatments were assessed: conventional (Conv) irrigation (I) and soil management (S) (ConvI+ConvS); modified (Mod) irrigation and soil management (ModI+ConvS); conventional irrigation and modified soil management (ConvI+ModS); and modified irrigation and soil management (ModI+ModS). Conventional irrigation and soil management in the tree row consisted of irrigation scheduling using tensiometer readings and herbicide use, respectively. Modified irrigation and soil management in the tree row consisted of water deprivation during stage III of fruit development and ground cover with white clover, respectively. For four consecutive years (2010–2013), in the conditions of the Middle Rhone Valley in France, the lowest and highest brown rot incidence were detected under (ModI+ModS) and (ConvI+ConvS), respectively, whereas brown rot incidence under (ModI+ConvS) and (ConvI+ModS) was intermediate. This lower brown rot incidence under the modified treatments occurred from one to two weeks before fruit maturity and was still observed for several days in post-harvest storage. Ground cover with white clover was shown to limit water availability in the soil after heavy rainfall compared to bare soil, probably limiting peach growth variations, well-known as a possible source of detrimental microcracks at the fruit surface. This suggests that under our conditions appropriate cultural practices, water deprivation and a clover crop cover in the tree row possibly decrease peach disease sensitivity, which might lead to the reduced use of pesticide sprays to control brown rot in the orchard.

Development of black-grass (Alopecurus myosuroides) in regard to different herbicide systems and soil management treatments

Am Standort Pettenbrunn, nordlich von Freising, wurde im Jahr 2011 ein Dauerversuch in einer Winterweizen-Monokultur zur Uberprufung der Populations- und Resistenzdynamik bei Acker-Fuchsschwanz ( Alopecurus myosuroides ) begonnen. Als Prufvarianten wurden vier unterschiedliche Herbizidregime und zwei verschiedene Bodenbearbeitungsverfahren durchgefuhrt. Die beiden Bodenbearbeitungsverfahren unterschieden sich durch eine wendende bzw. nicht-wendende Grundbodenbearbeitung. Als Erhebungen wurde die Besatzdichte an Acker-Fuchsschwanzpflanzen und Acker-Fuchsschwanzahren in den Behandlungsflachen und in unbehandelten Kontrollflachen festgestellt. Auserdem wurde anhand von Samenproben aus unbehandelten Kontrollflachen ein Biotest zur Uberprufung der Herbizidresistenz durchgefuhrt. Die Ergebnisse der Besatzdichteerhebungen und der Resistenzuntersuchungen werden fur den Versuchszeitraum 2011 bis 2015 dargestellt und auf der Basis einer Rangfolgeanalyse statistisch bewertet. Hinsichtlich der Entwicklung der Besatzdichte von Acker-Fuchsschwanz hatte die Art der Bodenbearbeitung einen signifikanten Einfluss. Die untersuchten Herbizidregime hatten lediglich auf den Besatz mit ahrentragenden Halmen in der behandelten Flache einen signifikanten Einfluss. In der Faktorkombination verursachte das Bodenbearbeitungsverfahren signifikante Unterschiede in der Besatzdichte. Innerhalb der nicht wendenden Bodenbearbeitung traten zusatzlich Differenzierungen zwischen den Herbizidregimen auf. Die Resistenzuntersuchungen zeigten einen signifikanten Einfluss des Bodenbearbeitungsverfahrens, wahrend zwischen den Herbizidregimen keine Differenzierung auftrat. In der Faktorkombination aus Bodenbearbeitung und Herbizidregime traten spezifische Differenzierungen auf. Fur die im Resistenztest gepruften Herbizide traten signifikante Differenzierungen zwischen den einzelnen Wirkstoffen und Wirkmechanismusgruppen auf. Die Ergebnisse zeigen eine Entwicklung der Populationsdynamik und Herbizidresistenz im Zusammenhang mit den Pruffaktoren, die offensichtlich noch nicht abgeschlossen ist und noch weiter untersucht werden muss. Development of black-grass ( Alopecurus myosuroides ) in regard to different herbicide systems and soil management treatments In 2011, a long-term field trial started in a winter wheat monoculture at Pettenbrunn, north of Freising, to examine the population and resistance dynamic of black-grass ( Alopecurus myosuroides ). Four different herbicide regimes and two different tillage methods were used as test factors. The two tillage methods were differentiated by a ploughing vs. non-ploughing primary soil tillage treatment. For the purpose of surveying of black-grass, the density of black-grass plants and seed heads in the treatment areas and in untreated control plots was assessed. In addition, a biotest to examine the herbicide resistance status was carried out using seed samples from untreated control areas. The results of the plant density survey and the resistance examinations are presented for the experiment period 2011 to 2015 and evaluated statistically on the basis of a ranking analysis. With regard to the development of the plant density of black-grass, the type of tillage had a significant influence. The herbicide regimes tested had a significant influence only on the number of seed heads in the treated area. In the factor combination, the method of tillage caused significant differences in plant density. In addition, there were also differences between the herbicide regimes within the non-ploughed plots. The resistance examinations showed a significant influence of the tillage method, while no differentiation emerged between the herbicide regimes. Specific differentiation occurred in the factor combination of tillage and herbicide regime. For the herbicides tested for resistance, significant differentiation occurred between the individual active ingredients and mode of action groups. The results show a development of the population dynamic and herbicide resistance in connection with the test factors, which are obviously not concluded and which must be further examined.