Arun Jani - Academia.edu (original) (raw)

Papers by Arun Jani

Plants

Biological nitrogen fixation in soybean is enhanced when seed is treated with cobalt (Co) and mol... more Biological nitrogen fixation in soybean is enhanced when seed is treated with cobalt (Co) and molybdenum (Mo) prior to planting. In this study, our objective was to verify if Co and Mo application during the reproductive phase of the crop increases seed Co and Mo concentration without adverse effects on seed quality. Two experiments were conducted. First, we investigated foliar and soil Co and Mo application under greenhouse conditions. Next, we validated the results obtained in the first study. The treatments for both experiments consisted of Co doses combined with Mo, and a control without Co and Mo application. The foliar application was more efficient in producing enriched Co and Mo seed; meanwhile, as Co doses increased so did Co and Mo concentrations in the seed. There were no adverse effects on nutrition, development, quality, and yield of parent plants and seed when these micronutrients were applied. The seed showed higher germination, vigor, and uniformity for the developme...

Soil and Tillage Research

Abstract Exploitation of tuff deposits represents an intensive and destructive human activity tha... more Abstract Exploitation of tuff deposits represents an intensive and destructive human activity that can completely modify natural soils, sometimes leading to their total disappearance. Soil reclamation of quarry areas can usually be done by soil rebuilding, employing complex and expensive techniques. In this research, we aimed to evaluate reconstructed Technosols and associated vegetation, called pedotechnosystem (PTS) and their development and behaviour for tuff quarry reclamation for both environmental rehabilitation and agricultural purposes. Technosols were investigated under three different conditions: i) a control consisting of a constructed Technosol (CT) without additional treatments; ii) CT treated with conventional mineral fertilization (CTCF); and, iii) CT treated with a composted mix of commercial organic amendments (CTOA). Different open-air mesocosms (pots) were investigated and evaluated in terms of: i) development, production, and metabolomic profile of rosemary (Rosmarinus officinalis L.), olive (Olea europaea L.), and grapevine (Vitis Vinifera L. ssp. Sativa) in a mixture with a pasture species: ii) the Technosols physical-chemical responses. Specifically, after 15 months, all investigated PTS were evaluated in terms of: i) pasture species total dry matter (TDM) production, height (H), stem diameter (D) and nitrogen (N), phosphorus (P), and potassium (K) content of dry matter; ii) physical-chemical analyses of all investigated substrates; iii) olive, grape, and rosemary characterization by analysing N, P, and K content in dry leaves as well as their metabolomic profile. Statistical differences among treatments were ascertained through ANOVA, while observed variability was interpreted using a principal factor analysis (PFA). Use of CTOA resulted in statistically (p

Agronomy

Some silicate rocks are a rich source of potassium (K), with the possibility for use in agricultu... more Some silicate rocks are a rich source of potassium (K), with the possibility for use in agriculture. The present study aimed to evaluate the agronomic efficiency index (AEI) of nepheline syenite (NS) and phonolite (PN) rocks in comparison with potassium chloride (KCl) as a K source in maize production. An experiment was conducted in a greenhouse in Ilha Solteira, São Paulo, Brazil. A maize hybrid was grown in 8 L pots filled with 6 kg of soil with a low K concentration and contrasting physical attributes (medium and sandy texture). A completely randomized design in a 3 × 6 factorial scheme was used, consisting of three K sources (NS, PN, and KCl) and six rates (0, 50, 100, 150, 200, and 400 mg kg−1) with four replications. All plants were harvested 45 days after emergence to evaluate biomass production, macronutrient (N, P, K, Ca, Mg, and S) concentration and uptake, stem diameter, and leaf chlorophyll index. After crop harvest, soil was collected for further chemical evaluation, wh...

Background The Diagnosis and Recommendation Integrated System (DRIS) gave valuable indices of the... more Background The Diagnosis and Recommendation Integrated System (DRIS) gave valuable indices of the nutritional status of Eucalyptus amended with sewage sludge (SS). Aims Our objective was to establish a DRIS norms and analytical method for Eucalyptus under SS application, by verifying in particular, the influence of potentially toxic elements (PTEs) on the nutritional and plant development. Method Data on mean annual increment, nutrient, and PTE concentration were obtained in an experiment at 22, 44, 54, and 76 months after planting Eucalyptus amended with SS. Results Our results indicated that DRIS can give valuable data on the nutritional balance indices, in which it was possible to verify that Ba was the most limiting element due to its excess present both in the low and high yielding subpopulations, ranging from 10 to 40% of the populations with excess of Ba. The nutritional diagnosis in agreement with the DRIS model ranged from 60 to 98% among the populations. When modeling the ...

Crops

High salt concentration in irrigation water is often a limiting factor to tomato production in Br... more High salt concentration in irrigation water is often a limiting factor to tomato production in Brazil. However, there is limited information available regarding the tolerance of tomato genotypes to saline irrigation. An experiment was conducted in a protected environment using a randomized block design with four replications. Treatments consisted of 12 tomato genotypes cultivated in an environment with varying levels of salt stress. Moderate and severe salt stress affected plant height, transversal and longitudinal diameter of fruit, fresh mass, yield, and number of tomato fruit per plant. Cluster analysis, stability, and adaptability provided the best estimates to identify the most adaptable genotype to saline stress, with the genotypes Maestrina, Onix, Pizzadoro, and Shanty being the best adapted to moderate and severe saline stress conditions. The genotypes Maestrina, Onix, Pizzadoro, and Shanty were identified as most adaptable to and stable under salt stress. Sodium absorption ...

Land

Mato Grosso do Sul State in Brazil is characterized by the ‘Cerrado’ ecoregion, which is the most... more Mato Grosso do Sul State in Brazil is characterized by the ‘Cerrado’ ecoregion, which is the most biologically rich Savannah globally. In agricultural terms, the region produces several commodities that are exported around the world. This level of productivity has been achieved through the large-scale use of synthetic fertilizers, which has created several economic and environmental concerns. New approaches in soil fertility management are required to avoid environmental degradation, pollution, and socio-environmental damages. A field experiment, lasting two years, was conducted to investigate the composted sewage sludge (CSS) effects on an infertile acidic soil (Oxisol) planted to maize (Zea mays L.). The following complete randomized complete block design with a 4 × 2 + 2 factorial scheme (four replications) was applied: four CSS increasing rates (from 5.0 to 12.5 Mg ha−1, w.b.) following two application methods (whole area and between crop rows). A control, without CSS or synthet...

Forest Ecology and Management

Experimental Agriculture

Legume agronomic research in Southern Africa has often focused on integrating legumes into smallh... more Legume agronomic research in Southern Africa has often focused on integrating legumes into smallholder cereal cropping systems, but there is limited information available on the feasibility and soil health implications of continuous cropping legumes in the region. Continuous legumes may be suitable in areas with large livestock populations where a premium is placed on high-quality forage, or where efforts are underway to reclaim degraded cropland. Our objectives in this study were to (i) evaluate the performance of diverse legumes under continuous cropping and conservation tillage management with no fertility inputs and (ii) assess the response of soil health parameters to continuous legumes in a semi-arid environment. A 4-year study was conducted in Limpopo, South Africa beginning in the 2011–2012 growing season in which 10 legume and fallow treatments were imposed in the same plots for 4 growing seasons. All legumes responded negatively in varying degrees to continuous cropping in...

Sustainability

Sugarcane demands large amounts of nutrients to reach a high level of productivity. Nutrients are... more Sugarcane demands large amounts of nutrients to reach a high level of productivity. Nutrients are generally supplied by mineral fertilizers, but their high costs and negative environmental impacts have generated interest in greater use of organic nutrient sources such as composted sewage sludge (CSS). In this study, we evaluated changes in soil chemical properties after the application of CSS or CSS/mineral fertilizer (MF) combinations to soil containing sugarcane seedlings under nursery conditions. Treatments included: T1: conventional mineral fertilization (MF) without application of CSS, T2: 100% of the recommended MF (06–30–24); T3: application of 2.5 Mg−1 CSS; T4: 5.0 Mg−1 CSS, T5: 7.5 Mg−1 CSS, T6: 2.5 Mg−1 CSS and 50% MF, T7: 5.0 Mg−1 CSS and 50% MF, T8: 7.5 Mg−1 CSS and 50% MF, T9: 2.5 Mg−1 CSS and 100% MF, T10: 5.0 Mg−1 CSS and 100% MF, T11: 7.5 Mg−1 CSS and 100% MF. Soil chemical properties were evaluated from the soil surface (0.0–0.25 m) and subsurface (0.25–0.50 m) hori...

Sustainability

Composted sewage sludge (CSS) contains large amounts of organic matter and nutrients and can be u... more Composted sewage sludge (CSS) contains large amounts of organic matter and nutrients and can be used as an organic fertilizer to improve growth, yield, and quality of sugarcane. However, there is a lack of information regarding the impact of CSS application on sugarcane seedling performance in nursery environments. A field study was conducted using a randomized complete block design to evaluate the development, nutritional status, productivity, and technological quality of sugarcane seedlings after CSS application with or without mineral fertilizer. Morphological variables (stem height, diameter, and number, as well as leaf area), technological attributes (total recoverable sugar: ATR; quantity of sucrose in sugarcane juice: Pol; Brix: percentage (weight/weight) of soluble solids contained in juice; TAH: tons of sugar per hectare), nutritional status, and sugarcane productivity were evaluated. Treatments did not influence morphological and technological variables except for TAH but ...

SSRN Electronic Journal, 2022

Environmental Monitoring and Assessment, 2021

With its accumulation in upland rice, cadmium (Cd) can easily enter the human food chain, which p... more With its accumulation in upland rice, cadmium (Cd) can easily enter the human food chain, which poses a global health threat considering nearly half of the human population depends on rice as a staple food source. A study was conducted to (1) evaluate Cd accumulation by rice cultivars, grown in Cd-polluted Tropical Oxisols, with different levels of Cd tolerance; (2) quantify Cd transfer from soil to rice shoots and grain; and (3) estimate daily Cd intake by humans. Three rice cultivars, characterized by low (Cateto Seda–CS), medium (BRSMG Talento–BT), and high (BRSMG Caravera–BC) Cd uptake capacity, were investigated. Rice cultivars were exposed to increasing soil Cd concentrations (0.0, 0.7, 1.3, 3.9, 7.8, and 11.7 mg kg−1). Analysis was performed on soil, shoots, and grain. Shoot biomass and grain yield decreased with increasing Cd supply, suggesting the following Cd tolerance: CS > BT > BC. Cadmium concentrations in shoots and grain increased when exposed to Cd. Only CS did not exceed the maximum Cd limit permitted in food (0.40 mg kg−1), when rates up to 1.3 mg kg−1 of Cd were applied to soil. Considering daily rice consumption levels in Brazil, Cd intake often exceeds maximum tolerable levels. Continuous monitoring of soil Cd concentrations is a pivotal step in avoiding hazards to humans. Such monitoring is important on a global scale since outside of Asia, Brazil is the leading rice-producing and rice-consuming country.

IOP Conference Series: Materials Science and Engineering, 2021

The objectives of our study were to evaluate i) the soil fertility and fractionation of Ba, Cd, C... more The objectives of our study were to evaluate i) the soil fertility and fractionation of Ba, Cd, Cu, and Zn in the topsoil layer (0-0.20 m depth); and ii) production and concentration and accumulation of Ba, Cd, Cu, and Zn in the components of Eucalyptus trees at 36 months after sewage sludge (SS) application, with or without mineral P fertilizer, compared to mineral fertilization. Application of SS (at N criteria) with P increased soil organic matter and heavy metal concentrations, which were mostly bound to the oxidic and organic matter fractions. SS provided Eucalyptus production and heavy metal concentrations and accumulation in the trunk, branches, and leaves similar to mineral fertilization for high wood production. The application of SS (at N criteria) supplied with P increased soil heavy metal, fertility, and Eucalyptus production, without risk of environmental contamination.

Revista Caatinga, 2021

This study aimed to determine how crop residue placement and composition would affect soil water ... more This study aimed to determine how crop residue placement and composition would affect soil water content and temperature during the dry season in the central region of Espírito Santo state, Brazil. A 19-week field study was conducted from April to August 2017. A 2 x 4 factorial study with four replications was implemented using a randomized complete block design. Factors were soil management [conventional tillage (CT) and no soil disturbance (ND)] and residue amendment [maize (Zea mays L.), sunn hemp (Crotalaria juncea L.), a maize-sunn hemp mixture, and a no amendment control]. Soil water content and temperature were measured weekly at predetermined soil depth intervals. Soil water content was higher in ND plots amended with surface residues than under all other treatments in the 0 to 0.05 m depth range. All residue amendments in this range were equally effective in conserving soil water. Surface residues reduced soil temperature by up to 8.4 °C relative to the control in ND plots....

Forest Ecology and Management, 2021

Abstract While deep soils commonly characterize tropical forests, direct measurements of soil phy... more Abstract While deep soils commonly characterize tropical forests, direct measurements of soil physical–chemical properties, fine root distributions, and relationships among them are scarce. In this paper, we report results from a project in Brazil that were obtained from experimental areas selected for their representative tropical climatic and edaphic features. Our objective was to evaluate vertical and spatial soil physical–chemical properties along the root-explored profile of Eucalyptus plantations to better understand the relationship between each component. Soil was collected from four sites (Tres Lagoas-Site 13, Mogi Guacu-20, Telemaco Borba-22, and Bocaiuva-30) and characterized for physical–chemical properties (pH, texture, organic matter, cation exchange capacity, and nutrient content) and fine root density (FRD). Soil was sampled up to 2 m beyond the deepest observed roots, or until a cemented horizon or R layer was detected. Spatial variability was investigated through a geostatistical approach using ordinary kriging. Data were subjected to ANOVA as well as bi- and multivariate statistics using a correlation matrix and robust principal factor analysis (PFA), respectively. Results showed that investigated Oxisols reached the maximum depth of 19 (Site 13), 8 (20), 11 (22), and 8 (30) m. In most investigated sites (20, 22, and 30) and for most soil properties, a typical soil horizonation was observed along the first 2.5/3.0 m. Deeper horizons (>3.0 m) of clayey Oxisols were characterized by the presence of typical porthole shapes dramatically interrupting soil horizonation, indicating spatial pedovariability and demonstrating underestimates of vertical and spatial pedovariability can occur under standard soil investigations to 2.0 m in depth. Correlation matrix and PFA showed that Eucalyptus roots strongly affected most investigated soil properties. Our study considered vertical and spatial dimensions of soil physical–chemical properties as well as the deep-rooting properties of Eucalyptus, which is critical for improving soil management in infertile Eucalyptus plantations.

HortScience, 2020

Since the arrival of Huanglongbing (HLB) disease in Florida, several management approaches, inclu... more Since the arrival of Huanglongbing (HLB) disease in Florida, several management approaches, including modification of orchard architecture design and nutritional therapy, have been explored. High-density plantings anticipate early economic returns from HLB-affected orchards. With no cure available for HLB, balanced nutrient application through soil and foliar spraying can mitigate the disease. A 2-year study was conducted to investigate the effects of three grapefruit (Citrus paradisi) planting densities [single-row (300 and 440 trees per ha), and double-row high-density (975 trees per ha)], two controlled-release fertilizer (CRF) blends, and foliar-applied micronutrients (FAM) (a blend of B, Mn, and Zn at 0, 1.5, 3, and 6 times the recommended rates) on grapefruit growth and fruit yield, physiological parameters, and foliar nutrient concentrations in an HLB-affected orchard. All the trees tested positive for HLB based on real-time quantitative polymerase chain reaction (qPCR) test....

Agricultural Water Management, 2021

Abstract Most citrus nurseries in Florida, USA use overhead irrigation, but subirrigation methods... more Abstract Most citrus nurseries in Florida, USA use overhead irrigation, but subirrigation methods, including ebb-and-flow and capillary mats, have been shown to conserve water and accelerate plant growth relative to overhead irrigation for other nursery species and may be a viable alternative to overhead irrigation in citrus liner production. The objectives of this study were to (1) automate an ebb-and-flow system for citrus liner production using capacitance sensors, and (2) evaluate how subirrigation and overhead irrigation methods affect water use, plant growth parameters, and substrate chemical properties. A study was conducted from 22 May to 23 September 2018 in which liners of six commercially important rootstock cultivars in cone-shaped containers were subjected to one of the following irrigation methods: ebb-and-flow triggered at substrate volumetric water contents (θ) of 0.24, 0.36, or 0.48 m3 m−3, capillary mats, and overhead irrigation. Capacitance sensors successfully monitored irrigation throughout the study. Ebb-and-flow benches used substantially less water (~411 L) than either capillary mats (13,098 L) or overhead irrigation (3193 L). By the end of the study, rootstock cultivars propagated using subirrigation methods were approximately 22% taller with 7% more total biomass than plants subjected to overhead irrigation. Additionally, plant growth at the 0.24 m3 m−3 threshold used to trigger ebb-and-flow was as great or greater than growth at 0.36 and 0.48 m3 m−3 thresholds. During the final five weeks of the study, substrate electrical conductivity was higher using subirrigation methods (0.84–1.3 ds m−1) than under overhead irrigation (0.55–0.8 ds m−1), but there were no symptoms of salt stress observed in plants at any time. Results from this study show that ebb-and-flow is a viable alternative to overhead irrigation and is superior to capillary mats for water conservation. In automated ebb-and-flow systems in Florida, we recommend using the 0.24 m3 m−3 threshold to produce the citrus rootstock cultivars used in this study with peat: perlite substrate.

EDIS, 2019

There is not enough evidence to support current peanut N credit recommendations in the Southeast.... more There is not enough evidence to support current peanut N credit recommendations in the Southeast. Nitrogen is released rapidly from peanut residues, and it moves quickly through light-textured soils found in this region. Only a relatively small amount of N from peanut residues is available when subsequent crops need it. This new 5-page document discusses peanut nitrogen credits, nitrogen release from peanut residues, crop performance following peanut, tillage and nitrogen release, and peanut residue distribution and nitrogen release. Written by Arun Jani and Michael J. Mulvaney, and published by the UF/IFAS Agronomy Department, April 2019. http://edis.ifas.ufl.edu/ag431

Horticulturae, 2020

Conventionally managed citrus orchards can be modified to incorporate advanced horticultural prac... more Conventionally managed citrus orchards can be modified to incorporate advanced horticultural practices such as higher plant density and efficient water and fertilizer application known as open hydroponics system (OHS) to increase productivity under Huanglongbing (HLB) endemic conditions. A field study was conducted from 2013 to 2018 to evaluate the effect of an OHS on “Ray Ruby” grapefruit (RR) production under HLB-endemic conditions. We tested a combination of different rootstocks [Sour orange (RR/SO) and US-897 (RR/897)], tree planting densities [standard (STD, 358 trees per ha) and high density staggered (HDS, 953 trees per ha)], fertilization methods (dry granular—dry and fertigation—fert), and irrigation systems (double driplines—DD and microsprinkler—MS), arranged in five treatments: RR/SO_STD_dry_MS, RR/SO_HDS_fert_DD, RR/897_HDS_fert_MS, RR/897_HDS_fert_DD, and RR/SO_HDS_fert_MS. All trees were infected by Candidatus Liberibacter asiaticus five years after planting. Trunk di...

Plants

Biological nitrogen fixation in soybean is enhanced when seed is treated with cobalt (Co) and mol... more Biological nitrogen fixation in soybean is enhanced when seed is treated with cobalt (Co) and molybdenum (Mo) prior to planting. In this study, our objective was to verify if Co and Mo application during the reproductive phase of the crop increases seed Co and Mo concentration without adverse effects on seed quality. Two experiments were conducted. First, we investigated foliar and soil Co and Mo application under greenhouse conditions. Next, we validated the results obtained in the first study. The treatments for both experiments consisted of Co doses combined with Mo, and a control without Co and Mo application. The foliar application was more efficient in producing enriched Co and Mo seed; meanwhile, as Co doses increased so did Co and Mo concentrations in the seed. There were no adverse effects on nutrition, development, quality, and yield of parent plants and seed when these micronutrients were applied. The seed showed higher germination, vigor, and uniformity for the developme...

Soil and Tillage Research

Abstract Exploitation of tuff deposits represents an intensive and destructive human activity tha... more Abstract Exploitation of tuff deposits represents an intensive and destructive human activity that can completely modify natural soils, sometimes leading to their total disappearance. Soil reclamation of quarry areas can usually be done by soil rebuilding, employing complex and expensive techniques. In this research, we aimed to evaluate reconstructed Technosols and associated vegetation, called pedotechnosystem (PTS) and their development and behaviour for tuff quarry reclamation for both environmental rehabilitation and agricultural purposes. Technosols were investigated under three different conditions: i) a control consisting of a constructed Technosol (CT) without additional treatments; ii) CT treated with conventional mineral fertilization (CTCF); and, iii) CT treated with a composted mix of commercial organic amendments (CTOA). Different open-air mesocosms (pots) were investigated and evaluated in terms of: i) development, production, and metabolomic profile of rosemary (Rosmarinus officinalis L.), olive (Olea europaea L.), and grapevine (Vitis Vinifera L. ssp. Sativa) in a mixture with a pasture species: ii) the Technosols physical-chemical responses. Specifically, after 15 months, all investigated PTS were evaluated in terms of: i) pasture species total dry matter (TDM) production, height (H), stem diameter (D) and nitrogen (N), phosphorus (P), and potassium (K) content of dry matter; ii) physical-chemical analyses of all investigated substrates; iii) olive, grape, and rosemary characterization by analysing N, P, and K content in dry leaves as well as their metabolomic profile. Statistical differences among treatments were ascertained through ANOVA, while observed variability was interpreted using a principal factor analysis (PFA). Use of CTOA resulted in statistically (p

Agronomy

Some silicate rocks are a rich source of potassium (K), with the possibility for use in agricultu... more Some silicate rocks are a rich source of potassium (K), with the possibility for use in agriculture. The present study aimed to evaluate the agronomic efficiency index (AEI) of nepheline syenite (NS) and phonolite (PN) rocks in comparison with potassium chloride (KCl) as a K source in maize production. An experiment was conducted in a greenhouse in Ilha Solteira, São Paulo, Brazil. A maize hybrid was grown in 8 L pots filled with 6 kg of soil with a low K concentration and contrasting physical attributes (medium and sandy texture). A completely randomized design in a 3 × 6 factorial scheme was used, consisting of three K sources (NS, PN, and KCl) and six rates (0, 50, 100, 150, 200, and 400 mg kg−1) with four replications. All plants were harvested 45 days after emergence to evaluate biomass production, macronutrient (N, P, K, Ca, Mg, and S) concentration and uptake, stem diameter, and leaf chlorophyll index. After crop harvest, soil was collected for further chemical evaluation, wh...

Background The Diagnosis and Recommendation Integrated System (DRIS) gave valuable indices of the... more Background The Diagnosis and Recommendation Integrated System (DRIS) gave valuable indices of the nutritional status of Eucalyptus amended with sewage sludge (SS). Aims Our objective was to establish a DRIS norms and analytical method for Eucalyptus under SS application, by verifying in particular, the influence of potentially toxic elements (PTEs) on the nutritional and plant development. Method Data on mean annual increment, nutrient, and PTE concentration were obtained in an experiment at 22, 44, 54, and 76 months after planting Eucalyptus amended with SS. Results Our results indicated that DRIS can give valuable data on the nutritional balance indices, in which it was possible to verify that Ba was the most limiting element due to its excess present both in the low and high yielding subpopulations, ranging from 10 to 40% of the populations with excess of Ba. The nutritional diagnosis in agreement with the DRIS model ranged from 60 to 98% among the populations. When modeling the ...

Crops

High salt concentration in irrigation water is often a limiting factor to tomato production in Br... more High salt concentration in irrigation water is often a limiting factor to tomato production in Brazil. However, there is limited information available regarding the tolerance of tomato genotypes to saline irrigation. An experiment was conducted in a protected environment using a randomized block design with four replications. Treatments consisted of 12 tomato genotypes cultivated in an environment with varying levels of salt stress. Moderate and severe salt stress affected plant height, transversal and longitudinal diameter of fruit, fresh mass, yield, and number of tomato fruit per plant. Cluster analysis, stability, and adaptability provided the best estimates to identify the most adaptable genotype to saline stress, with the genotypes Maestrina, Onix, Pizzadoro, and Shanty being the best adapted to moderate and severe saline stress conditions. The genotypes Maestrina, Onix, Pizzadoro, and Shanty were identified as most adaptable to and stable under salt stress. Sodium absorption ...

Land

Mato Grosso do Sul State in Brazil is characterized by the ‘Cerrado’ ecoregion, which is the most... more Mato Grosso do Sul State in Brazil is characterized by the ‘Cerrado’ ecoregion, which is the most biologically rich Savannah globally. In agricultural terms, the region produces several commodities that are exported around the world. This level of productivity has been achieved through the large-scale use of synthetic fertilizers, which has created several economic and environmental concerns. New approaches in soil fertility management are required to avoid environmental degradation, pollution, and socio-environmental damages. A field experiment, lasting two years, was conducted to investigate the composted sewage sludge (CSS) effects on an infertile acidic soil (Oxisol) planted to maize (Zea mays L.). The following complete randomized complete block design with a 4 × 2 + 2 factorial scheme (four replications) was applied: four CSS increasing rates (from 5.0 to 12.5 Mg ha−1, w.b.) following two application methods (whole area and between crop rows). A control, without CSS or synthet...

Forest Ecology and Management

Experimental Agriculture

Legume agronomic research in Southern Africa has often focused on integrating legumes into smallh... more Legume agronomic research in Southern Africa has often focused on integrating legumes into smallholder cereal cropping systems, but there is limited information available on the feasibility and soil health implications of continuous cropping legumes in the region. Continuous legumes may be suitable in areas with large livestock populations where a premium is placed on high-quality forage, or where efforts are underway to reclaim degraded cropland. Our objectives in this study were to (i) evaluate the performance of diverse legumes under continuous cropping and conservation tillage management with no fertility inputs and (ii) assess the response of soil health parameters to continuous legumes in a semi-arid environment. A 4-year study was conducted in Limpopo, South Africa beginning in the 2011–2012 growing season in which 10 legume and fallow treatments were imposed in the same plots for 4 growing seasons. All legumes responded negatively in varying degrees to continuous cropping in...

Sustainability

Sugarcane demands large amounts of nutrients to reach a high level of productivity. Nutrients are... more Sugarcane demands large amounts of nutrients to reach a high level of productivity. Nutrients are generally supplied by mineral fertilizers, but their high costs and negative environmental impacts have generated interest in greater use of organic nutrient sources such as composted sewage sludge (CSS). In this study, we evaluated changes in soil chemical properties after the application of CSS or CSS/mineral fertilizer (MF) combinations to soil containing sugarcane seedlings under nursery conditions. Treatments included: T1: conventional mineral fertilization (MF) without application of CSS, T2: 100% of the recommended MF (06–30–24); T3: application of 2.5 Mg−1 CSS; T4: 5.0 Mg−1 CSS, T5: 7.5 Mg−1 CSS, T6: 2.5 Mg−1 CSS and 50% MF, T7: 5.0 Mg−1 CSS and 50% MF, T8: 7.5 Mg−1 CSS and 50% MF, T9: 2.5 Mg−1 CSS and 100% MF, T10: 5.0 Mg−1 CSS and 100% MF, T11: 7.5 Mg−1 CSS and 100% MF. Soil chemical properties were evaluated from the soil surface (0.0–0.25 m) and subsurface (0.25–0.50 m) hori...

Sustainability

Composted sewage sludge (CSS) contains large amounts of organic matter and nutrients and can be u... more Composted sewage sludge (CSS) contains large amounts of organic matter and nutrients and can be used as an organic fertilizer to improve growth, yield, and quality of sugarcane. However, there is a lack of information regarding the impact of CSS application on sugarcane seedling performance in nursery environments. A field study was conducted using a randomized complete block design to evaluate the development, nutritional status, productivity, and technological quality of sugarcane seedlings after CSS application with or without mineral fertilizer. Morphological variables (stem height, diameter, and number, as well as leaf area), technological attributes (total recoverable sugar: ATR; quantity of sucrose in sugarcane juice: Pol; Brix: percentage (weight/weight) of soluble solids contained in juice; TAH: tons of sugar per hectare), nutritional status, and sugarcane productivity were evaluated. Treatments did not influence morphological and technological variables except for TAH but ...

SSRN Electronic Journal, 2022

Environmental Monitoring and Assessment, 2021

With its accumulation in upland rice, cadmium (Cd) can easily enter the human food chain, which p... more With its accumulation in upland rice, cadmium (Cd) can easily enter the human food chain, which poses a global health threat considering nearly half of the human population depends on rice as a staple food source. A study was conducted to (1) evaluate Cd accumulation by rice cultivars, grown in Cd-polluted Tropical Oxisols, with different levels of Cd tolerance; (2) quantify Cd transfer from soil to rice shoots and grain; and (3) estimate daily Cd intake by humans. Three rice cultivars, characterized by low (Cateto Seda–CS), medium (BRSMG Talento–BT), and high (BRSMG Caravera–BC) Cd uptake capacity, were investigated. Rice cultivars were exposed to increasing soil Cd concentrations (0.0, 0.7, 1.3, 3.9, 7.8, and 11.7 mg kg−1). Analysis was performed on soil, shoots, and grain. Shoot biomass and grain yield decreased with increasing Cd supply, suggesting the following Cd tolerance: CS > BT > BC. Cadmium concentrations in shoots and grain increased when exposed to Cd. Only CS did not exceed the maximum Cd limit permitted in food (0.40 mg kg−1), when rates up to 1.3 mg kg−1 of Cd were applied to soil. Considering daily rice consumption levels in Brazil, Cd intake often exceeds maximum tolerable levels. Continuous monitoring of soil Cd concentrations is a pivotal step in avoiding hazards to humans. Such monitoring is important on a global scale since outside of Asia, Brazil is the leading rice-producing and rice-consuming country.

IOP Conference Series: Materials Science and Engineering, 2021

The objectives of our study were to evaluate i) the soil fertility and fractionation of Ba, Cd, C... more The objectives of our study were to evaluate i) the soil fertility and fractionation of Ba, Cd, Cu, and Zn in the topsoil layer (0-0.20 m depth); and ii) production and concentration and accumulation of Ba, Cd, Cu, and Zn in the components of Eucalyptus trees at 36 months after sewage sludge (SS) application, with or without mineral P fertilizer, compared to mineral fertilization. Application of SS (at N criteria) with P increased soil organic matter and heavy metal concentrations, which were mostly bound to the oxidic and organic matter fractions. SS provided Eucalyptus production and heavy metal concentrations and accumulation in the trunk, branches, and leaves similar to mineral fertilization for high wood production. The application of SS (at N criteria) supplied with P increased soil heavy metal, fertility, and Eucalyptus production, without risk of environmental contamination.

Revista Caatinga, 2021

This study aimed to determine how crop residue placement and composition would affect soil water ... more This study aimed to determine how crop residue placement and composition would affect soil water content and temperature during the dry season in the central region of Espírito Santo state, Brazil. A 19-week field study was conducted from April to August 2017. A 2 x 4 factorial study with four replications was implemented using a randomized complete block design. Factors were soil management [conventional tillage (CT) and no soil disturbance (ND)] and residue amendment [maize (Zea mays L.), sunn hemp (Crotalaria juncea L.), a maize-sunn hemp mixture, and a no amendment control]. Soil water content and temperature were measured weekly at predetermined soil depth intervals. Soil water content was higher in ND plots amended with surface residues than under all other treatments in the 0 to 0.05 m depth range. All residue amendments in this range were equally effective in conserving soil water. Surface residues reduced soil temperature by up to 8.4 °C relative to the control in ND plots....

Forest Ecology and Management, 2021

Abstract While deep soils commonly characterize tropical forests, direct measurements of soil phy... more Abstract While deep soils commonly characterize tropical forests, direct measurements of soil physical–chemical properties, fine root distributions, and relationships among them are scarce. In this paper, we report results from a project in Brazil that were obtained from experimental areas selected for their representative tropical climatic and edaphic features. Our objective was to evaluate vertical and spatial soil physical–chemical properties along the root-explored profile of Eucalyptus plantations to better understand the relationship between each component. Soil was collected from four sites (Tres Lagoas-Site 13, Mogi Guacu-20, Telemaco Borba-22, and Bocaiuva-30) and characterized for physical–chemical properties (pH, texture, organic matter, cation exchange capacity, and nutrient content) and fine root density (FRD). Soil was sampled up to 2 m beyond the deepest observed roots, or until a cemented horizon or R layer was detected. Spatial variability was investigated through a geostatistical approach using ordinary kriging. Data were subjected to ANOVA as well as bi- and multivariate statistics using a correlation matrix and robust principal factor analysis (PFA), respectively. Results showed that investigated Oxisols reached the maximum depth of 19 (Site 13), 8 (20), 11 (22), and 8 (30) m. In most investigated sites (20, 22, and 30) and for most soil properties, a typical soil horizonation was observed along the first 2.5/3.0 m. Deeper horizons (>3.0 m) of clayey Oxisols were characterized by the presence of typical porthole shapes dramatically interrupting soil horizonation, indicating spatial pedovariability and demonstrating underestimates of vertical and spatial pedovariability can occur under standard soil investigations to 2.0 m in depth. Correlation matrix and PFA showed that Eucalyptus roots strongly affected most investigated soil properties. Our study considered vertical and spatial dimensions of soil physical–chemical properties as well as the deep-rooting properties of Eucalyptus, which is critical for improving soil management in infertile Eucalyptus plantations.

HortScience, 2020

Since the arrival of Huanglongbing (HLB) disease in Florida, several management approaches, inclu... more Since the arrival of Huanglongbing (HLB) disease in Florida, several management approaches, including modification of orchard architecture design and nutritional therapy, have been explored. High-density plantings anticipate early economic returns from HLB-affected orchards. With no cure available for HLB, balanced nutrient application through soil and foliar spraying can mitigate the disease. A 2-year study was conducted to investigate the effects of three grapefruit (Citrus paradisi) planting densities [single-row (300 and 440 trees per ha), and double-row high-density (975 trees per ha)], two controlled-release fertilizer (CRF) blends, and foliar-applied micronutrients (FAM) (a blend of B, Mn, and Zn at 0, 1.5, 3, and 6 times the recommended rates) on grapefruit growth and fruit yield, physiological parameters, and foliar nutrient concentrations in an HLB-affected orchard. All the trees tested positive for HLB based on real-time quantitative polymerase chain reaction (qPCR) test....

Agricultural Water Management, 2021

Abstract Most citrus nurseries in Florida, USA use overhead irrigation, but subirrigation methods... more Abstract Most citrus nurseries in Florida, USA use overhead irrigation, but subirrigation methods, including ebb-and-flow and capillary mats, have been shown to conserve water and accelerate plant growth relative to overhead irrigation for other nursery species and may be a viable alternative to overhead irrigation in citrus liner production. The objectives of this study were to (1) automate an ebb-and-flow system for citrus liner production using capacitance sensors, and (2) evaluate how subirrigation and overhead irrigation methods affect water use, plant growth parameters, and substrate chemical properties. A study was conducted from 22 May to 23 September 2018 in which liners of six commercially important rootstock cultivars in cone-shaped containers were subjected to one of the following irrigation methods: ebb-and-flow triggered at substrate volumetric water contents (θ) of 0.24, 0.36, or 0.48 m3 m−3, capillary mats, and overhead irrigation. Capacitance sensors successfully monitored irrigation throughout the study. Ebb-and-flow benches used substantially less water (~411 L) than either capillary mats (13,098 L) or overhead irrigation (3193 L). By the end of the study, rootstock cultivars propagated using subirrigation methods were approximately 22% taller with 7% more total biomass than plants subjected to overhead irrigation. Additionally, plant growth at the 0.24 m3 m−3 threshold used to trigger ebb-and-flow was as great or greater than growth at 0.36 and 0.48 m3 m−3 thresholds. During the final five weeks of the study, substrate electrical conductivity was higher using subirrigation methods (0.84–1.3 ds m−1) than under overhead irrigation (0.55–0.8 ds m−1), but there were no symptoms of salt stress observed in plants at any time. Results from this study show that ebb-and-flow is a viable alternative to overhead irrigation and is superior to capillary mats for water conservation. In automated ebb-and-flow systems in Florida, we recommend using the 0.24 m3 m−3 threshold to produce the citrus rootstock cultivars used in this study with peat: perlite substrate.

EDIS, 2019

There is not enough evidence to support current peanut N credit recommendations in the Southeast.... more There is not enough evidence to support current peanut N credit recommendations in the Southeast. Nitrogen is released rapidly from peanut residues, and it moves quickly through light-textured soils found in this region. Only a relatively small amount of N from peanut residues is available when subsequent crops need it. This new 5-page document discusses peanut nitrogen credits, nitrogen release from peanut residues, crop performance following peanut, tillage and nitrogen release, and peanut residue distribution and nitrogen release. Written by Arun Jani and Michael J. Mulvaney, and published by the UF/IFAS Agronomy Department, April 2019. http://edis.ifas.ufl.edu/ag431

Horticulturae, 2020

Conventionally managed citrus orchards can be modified to incorporate advanced horticultural prac... more Conventionally managed citrus orchards can be modified to incorporate advanced horticultural practices such as higher plant density and efficient water and fertilizer application known as open hydroponics system (OHS) to increase productivity under Huanglongbing (HLB) endemic conditions. A field study was conducted from 2013 to 2018 to evaluate the effect of an OHS on “Ray Ruby” grapefruit (RR) production under HLB-endemic conditions. We tested a combination of different rootstocks [Sour orange (RR/SO) and US-897 (RR/897)], tree planting densities [standard (STD, 358 trees per ha) and high density staggered (HDS, 953 trees per ha)], fertilization methods (dry granular—dry and fertigation—fert), and irrigation systems (double driplines—DD and microsprinkler—MS), arranged in five treatments: RR/SO_STD_dry_MS, RR/SO_HDS_fert_DD, RR/897_HDS_fert_MS, RR/897_HDS_fert_DD, and RR/SO_HDS_fert_MS. All trees were infected by Candidatus Liberibacter asiaticus five years after planting. Trunk di...