Reduced Bulk Density Research Articles

Experimental and finite element analysis on thermal conductivity of burnt clay bricks reinforced with fibers

Buildings consume more than 30% of primary energy in order to maintain their indoor temperature which varied due to heating and cooling losses. This energy consumption has been increased dramatically through the last decade due to population explosion, more time is spent indoors along with climate changes. Energy efficient building materials are the ultimate requirement and several insulating materials have been developed to minimize the carbon foot prints. Current research work deals with the conversion of conventional terra cotta brick to porous low thermal conductive brick using various organic fibers. Bamboo, jute, coir, sisal and polyester fibers are used in this research work while all having low embodied energy. Water absorption index of fibers and brick, bulk density and porosity of all types of bricks were measured and relationships with water absorption were also established. Reduction in thermal conductivity was observed, using steady state conduction apparatus: upto 18% reduction in thermal conductivity. Reduction in bulk density, thermal conductivity, and increase in water absorption were all attributed to porosity created by burning of fibers. Thermal conductivity was also estimated analytically by using finite element simulation using ANSYS platform, heat flow and temperature at both ends were selected parameters for input, whereas heat flux and temperature gradient were output. The maximum difference between experimental and analytical thermal conductivity was varied up to 7.8%, which verify its applicability.

Perlite as the partial substitute for organic bulking agent during sewage sludge composting.

Composting is an efficient and cost-effective technology for sewage sludge treatment, and bulking agents are essential in sewage sludge composting. In this study, perlite was chosen as inorganic bulking agent to partially substitute for the organic bulking agent. Variations in the temperature, bulk density, moisture content, pH, electrical conductivity, organic carbon, nitrogen, phosphorus and potassium were detected during sewage sludge composting. The treatment with a mass ratio of spent mushroom substrate to perlite at 3:1 exhibited the highest pile temperature and the best effect on reducing bulk density and moisture content. In addition, Fourier transform infrared spectra showed that perlite promotes the degradation of organic matter during the composting process, and the germination index showed that the compost from all treatments was safe for agricultural application. When the mass ratios of spent mushroom substrate and perlite at 3:1 and 2:2 were chosen as bulking agents, the sewage sludge compost product could be used to produce plant cultivation substrate, and economic benefits could be obtained from sewage sludge composting according to comprehensive cost analysis.

Effect on germination time and temperature on techno-functional properties and protein solubility of pigeon pea (Cajanus cajan) flour

Germination is a natural low-cost bioprocessing technique that can be used to enhance the functionality of food grains. The present study evaluates the effect of germination time and temperature on the functional characteristics and protein solubility of germinated pigeon pea flour. Germinated pigeon pea flour exhibited a reduction in bulk density, water absorption and swelling power, as well as an enhanced gelling consistency and oil absorption capacity in comparison to raw flour due to enzymatic modification of starch and proteins. Germination for 48 h at 35 °C decreased the paste clarity of processed flour, while synereis of flour was increased. Prolonged germination time positively increased the protein solubility and least gelation concentration of pigeon pea flour. Raw flour showed the lowest emulsion and foaming properties, while an increase in germination conditions increased the emulsifying and foaming properties of the flour.

Soil Properties, Okra Performance and Nutrient Compositions as Affected by Tillage and Maize Cob Ash

Alfisols, the dominant soil order in southwest Nigeria in which crops are grown possess unfavorable peculiarities such as low inherent fertility and acidity. These limitations can be ameliorated by tillage and organic manuring. Therefore, field experiments were conducted during the 2014 and 2015 cropping seasons to assess the effects of tillage methods and maize cob ash (MCA) on soil properties, yield, growth, mineral, and vitamin C contents of okra fruit. The experiment consisted of 3 × 3 factorial combinations of three tillage methods {zero–tillage ZT, manual ridging MR, and plowing plus harrowing P+H} and three rates (0.0, 3.0, and 6.0 t ha−1) of application of MCA. Tillage methods and MCA influenced soil physical and chemical properties, performance, mineral and vitamin C contents of okra fruit significantly. MCA increased soil K, Ca, Mg, okra yield, growth, mineral and vitamin C contents of okra fruits up to 3 t ha−1 level after which there was a decrease. The order of reducing bulk density and soil chemical properties, increasing porosity, yield, growth, mineral and vitamin C contents of okra was: ZT > MR > P+H. Tillage appears to be indispensable for sustainable okra production on Alfisol of southwest Nigeria. Growth and yield of okra in this study was dependent on soil physical properties and chemical properties such as pH, OM, N, and K. Combination of P+H and 3 t ha−1 MCA produced better yield, growth, mineral and vitamin C contents of okra compared with other combinations of tillage with MCA. Addition of MCA to either P+H or MR is important to reduce the limitation of acidity associated with tropical Alfisol.

Soil water retention, physiological characteristics, and growth of maize plants in response to biochar application to soil

Studies on biochar application in agriculture are broad, but the effects are variable and depend on the type of plant, biochar properties, and application rate, as well as some soil characteristics and environmental conditions. This study aimed to assess the effect of applying different doses of biochar with two particle sizes on the physical and chemical characteristics of a Typic Haplustox, sandy loam, and on the growth and physiological characters of maize plants, under two soil moisture conditions. The study was conducted in a greenhouse, using two biochar particle sizes (2.0−0.5 and < 0.5 mm), at six doses (0, 5, 10, 20, 40 and 60 g kg−1) and two water conditions (with and without drought stress). The plant characters assessed were height, stem diameter, leaf area, shoot fresh and dry weight, and nutritional status. Leaf relative water content, photosynthesis, and stomatal conductance were evaluated under drought stress. The soil attributes studied were density, porosity, water retention curve, and hydrophobicity, in addition to chemical characterization. There were no statistical differences between the two biochar particle sizes, except for bulk density and microporosity. Under adequate water conditions, and two doses of biochar applied to the soil increased photosynthesis, stomatal conductance, and leaf relative water content in the sewn corn. In the soil, biochar raised water retention and the micropore/macropore ratio and reduced bulk density, in addition to improving fertility. High biochar doses improved soil fertility as well as plant nutritional status and development. The increased water retention as a consequence of biochar amendment was not sufficient to overcome drought stress problems in the soil.

Impacts of Municipal Wastewater on The Transport Characteristics of Reactive Solutes Through Agricultural Soils

ABSTRACTReliable transport parameters of agrochemicals and soluble pollutants are crucial for modeling and management of soil and groundwater quality. This study investigated impacts of municipal wastewater on the transport parameters of five heavy metal/metalloid compounds (NaAsO2, Cd(NO3)2, Pb(NO3)2, Ni(NO3)2 & ZnCl2), two pesticides (cartap & carbendazim) and an inert salt (CaCl2) in four agricultural soils of Bangladesh. Solute-breakthrough concentrations were measured in repacked soil columns with time-domain reflectometry (TDR) both before and after wastewater treatment. Transport velocity (V), dispersion coefficient (D), dispersivity (λ) and retardation factor (R) of the solutes, and pertinent soil properties were determined. Wastewater reduced bulk density (γ) of the soils (from 1.32–1.37 g/cm3 to 1.26–1.35 g/cm3) by increasing organic carbon (OC) (from 0.37%–0.84% to 0.40–0.93%), increased pore-size distribution index (n) (by 0.02 unit) and reduced soil pH (from 6.32–7.45 to 5.92–6.46). D and λ decreased while V and R increased after wastewater treatment; D decreased and R increased linearly with decreasing bulk density. The correlations of V, D, and R with n improved significantly (p < 0.05) after wastewater treatment. The correlation between λ and OC improved markedly for Ca, Pb, Ni, and cartap. The observed indicative results have practical implications in developing pedo-transfer functions for solute-transport parameters using basic soil properties, which are subject to progressive modification due to agrochemicals application and wastewater irrigation.

Experimental study on the performance characteristics of viscous debris flows with a grid-type dam for debris flow hazards mitigation

A grid-type dam, which is an open-type dam, is an active structural countermeasure employed to mitigate the potential risk from and damage by debris flows. Although grid-type dams are widely used to control water-stone flows in Japan and other countries, they are not used in China due to the lack of knowledge regarding their suitability for controlling viscous debris flows. Viscous debris flows with a wide grain-size distribution are common in southwestern China. Using the known characteristics of such debris flows, we performed a series of flume tests designed to take three main factors into account: debris flow bulk density, channel gradient, and grid size. The goal of these tests was to investigate the dynamic processes and the performance of a grid-type dam in controlling viscous debris flows. The results of our analysis indicated that grid-type dams could effectively trap and regulate viscous debris flows. The sediment storage rate increased with the bulk density, concomitantly with a decrease in the reduction rate of bulk density and peak discharge; however, all parameters decreased with grid opening size. Additionally, based on theoretical analyses and experimental results, dimensionless relationship equations for grid-type dams were established that considered sediment storage rate, bulk density reduction rate, and peak discharge reduction rate. These equations make it possible to predict the effectiveness of controlling transported sediment using a grid-type dam. Moreover, they represent a reference for designing grid opening size, which could provide technical support for further practical engineering. Finally, we applied these equations to a case study of the Sandaoqiao Gully, where they were shown to be effective as a guideline in designing a grid-type dam to control a viscous debris flow.

Impact of Farmland Abandonment on Water Resources and Soil Conservation in Citrus Plantations in Eastern Spain

Due to the reduction in the prices of oranges on the market and social changes such as the ageing of the population, traditional orange plantation abandonment in the Mediterranean is taking place. Previous research on land abandonment impact on soil and water resources has focused on rainfed agriculture abandonment, but there is no research on irrigated land abandonment. In the Valencia Region—the largest producer of oranges in Europe—abandonment is resulting in a quick vegetation recovery and changes in soil properties, and then in water erosion. Therefore, we performed rainfall simulation experiments (0.28 m2; 38.8 mm h−1) to determine the soil losses in naveline orange plantations with different ages of abandonment (1, 2, 3, 5, 7 and 10 years of abandonment) which will allow for an understanding of the temporal changes in soil and water losses after abandonment. Moreover, these results were also compared with an active plantation (0). The results show that the soils of the active orange plantations have higher runoff discharges and higher erosion rates due to the use of herbicides than the plots after abandonment. Once the soil is abandoned for one year, the plant recovery reaches 33% of the cover and the erosion rate drops one order of magnitude. This is related to the delay in the runoff generation and the increase in infiltration rates. After 2, 3, 5, 7 and 10 years, the soil reduced bulk density, increase in organic matter, plant cover, and soil erosion rates were found negligible. We conclude that the abandonment of orange plantations reduces soil and water losses and can serve as a nature-based solution to restore the soil services, goods, and resources. The reduction in the soil losses was exponential (from 607.4 g m−2 in the active plot to 7.1 g m−2 in the 10-year abandoned one) but the water losses were linear (from 77.2 in active plantations till 12.8% in the 10-year abandoned ones).

Soil physical properties of a Luvisol developed on loess after 15 years of amendment with compost

Recycling composted organic residues in agriculture can reduce the need for mineral fertilizers and improve the physicochemical and biological properties of cultivated soils. However, more studies dealing with soil physical properties after compost amendment are still needed. The objective of this study was to investigate the impact of long-term compost amendment on soil physical properties in a silt loam Luvisol under a maize-wheat rotation in the Paris Basin. Since 1998, three composts and one manure were applied every second year after wheat harvest, at a rate of ca. 4 Mg C ha−1. Bulk density, organic carbon concentration on a mass basis, water holding capacity, gas transport properties and Atterberg limits were measured on topsoil samples taken 15 years after the beginning of the experiment. Soil moisture was monitored in the field down to a depth of 160 cm during two years with different climatic conditions: a year with a dry summer (2010) and a year with a wet summer (2012). Compost and manure amendments reduced bulk density and increased organic carbon concentrations, which improved apparent air permeability and gas diffusivity, but only one of the amendments (a green waste-sewage sludge compost) increased water-holding capacity. The amendments also increased the water contents at the Atterberg limits and overall produced better soil conditions for tillage and other agricultural operations, in particular in wet years. However, field moisture measurements showed that in general, soil water contents were not higher in the amended soils than in the control at any of the periods considered.

Structuring of a Haplortox by Cover Crops and Their Effects on the Yield of Soybean Grains

The intense agricultural machinery traffic over the plantation ground can lead the erosion and growth difficulty. The goal of this study was to evaluate the soya bean yield after the implantation of species named &amp;ldquo;recoverable&amp;rdquo;, of soil structure. The experiment was developed in plots of 20 m &amp;times; 25 m, located in the Agronomic Institute of Parana (IAPAR), in Santa Tereza do Oeste, Paran&amp;aacute;. The plots were cultivated by direct sowing of the following species, considered as treatments: sunn hemp (Crotalaria juncea), rattlebox (Crotalaria spectabilis), velvet bean (Mucuna aterrima), pearl millet (Pennisetum glaucum), pigeon pea (Cajanus cajan), dwarf pigeon pea (Cajanus cajan) beside them no-tillage and no-cover crop planting traditional system (control). Soil samples were collected from 0-10 cm, 10-20 cm, and 20-30 cm-layers with 4 repetitions on each treatment. Soil density and porous soil space were also determined. The plot yield of soybean grains was evaluated over an area of 4.5 m2 for each treatment and grain moisture corrected to 13%. The treatments&amp;rsquo; mean yields were compared using the Tukey test at 5% probability. The dwarf pigeon pea and the rattlebox were the most efficient cover crops in the reduction of soil bulk density in 0-10 and 10-20 cm depths. The soybean grain yield did not differ between the evaluated treatments, possibly due to the good precipitation conditions during the soybean growing cycle.

Impacts of Municipal Wastewater on Basic Soil Properties as Evaluated by Soil Column Leaching Experiment in Laboratory

Functional relationships between wastewater-induced predictors (e.g., organic carbon, OC) and amended soil properties are needed to develop pedo-transfer functions for wastewater-amended/-irrigated soils. The objective of this study was to determine the impacts of municipal wastewater on soil health and develop functional relationships between wastewater-amended soil hydro-physico-chemical properties. The objectives were realized by conducting laboratory experiments on repacked columns of four typical agricultural soils. The soil columns, after primary settlement over 7 months, were conditioned by applying tap water over 6 months and then a typical quality wastewater in nine irrigations (total 90 cm, equivalent to irrigation requirement for three wheat seasons) over the next 8 months with an irrigation interval of 25 days. Each irrigation amounting 10 cm wastewater was applied in 5 days (2 cm d−1). Wastewater significantly (p < 0.05) elevated OC (13.85%) but reduced bulk density (3.73%) of the soils; bulk density decreased linearly with OC with a strong correlation (r2 = 0.90). The negative correlation between pore-size distribution index and clay content of the soils became significant (p < 0.05) after wastewater treatment. Plant available soil-water content increased linearly (r2 = 0.71) with increasing micro-porosity. The magnitudes of soil-properties change are however soil- and wastewater-type dependent functions. Municipal wastewater can be used to improve hydro-physico-chemical properties of soils and the strong functional relationships between wastewater-amended predictors (e.g., OC) and predictands (e.g., bulk density) can be used for designing and managing soil amendment and irrigation with wastewater.

Assessment of Soil-Water Infiltration Dynamics of Waste Oil Polluted Terrestrial Habitat Under Macrophytic Remediation: A Window for Automobile Workshops

Automobile workshops are the hub of waste oil sources among other sources of pollution with it attendance consequence of physico-edaphic alterations of the terrestrial soil habitat. This research was aimed at reevaluating the demonstrated potential of three hydrocarbon tolerant leguminous species; in view of their application in automobile workshop surroundings. Field and laboratory analysis of the physico-edaphic parameters were carried out using universally acceptable standard methods. Result has recorded enhanced infiltration rate by phytotechnology among Peltophorum pterocarpium (Pp), Leucaena leucocephala (Ll) and Crotolaria retusa (Cr) waste oil soils in the order Pp&lt;Cl&lt;Ll ; in which P. pterocarpum has increased infiltration at lesser time rate of 1.07 ± 0.31, 1.51 ± 0.02, 2.48 ± 0.35 and 3.13 ± 1.45 across levels of treatment with significant difference ( p&lt;0.05 ). This was correspondingly in direct relationship with the significantly enhanced particle size (87.73%) of sand, and 2.61g/cm 3 particle density, reduced bulk density (0.83g/cm 3 ), 68% porosity increase and reduced organic matter content of 2.65%, total hydrocarbon content reduction of 1.8mg/g, high efficiency of 55% hydrocarbon removal, 34.40 bioaccumulation quotient and 24.63% reduction in crusting hazard of sealing recorded. Conclusively, P. pterocarpum can be proposed for automobile workshops as a proactive measure and containment absorbent among other hydrocarbon restoration approach against envisaged waste oil discharge. Keywords: Crusting hazard, total hydrocarbon, root formation, bioaccumulation quotient and particle size. DOI : 10.7176/JEES/9-3-07 Publication date :March 31 st 2019

Influence of Digestate on Physical Properties of Soil in ZD Budišov

One of the main objectives of crop establishment is adjustment of physical properties of soil, on which indicators of soil fertility as well as economic appreciation of the resulting yield depend. During 2014–2016 yield of corn and sorghum was observed in semi‑operational experiments of ZD Budišov in relation to the quantity of the applied digestate and simultaneously, the following physical properties of soil were analysed: porosity, compaction and soil structure. After the application of digestate the porosity and minimal air capacity decreased, and reduced bulk density increased. Soil structure was affected negatively too. Overall, a trend of degradation of physical state of soil in variant with doubled dose of applied digestate was registered. Yields were always higher in variants with digestate due to a higher supply of higher amount of nutrients. Results of this observation indicate that crop yields may be higher but at the same time physical properties of soil may be impaired which may, while increasing doses of digestate, lead to irreversible degradation of soil.

Sub-soiling improves productivity and economic returns of cotton-wheat cropping system

Soil compaction in Indian Punjab is an emerging problem affecting crop productivity. Heavy machinery operations or repetitive tillage in fields are main reasons behind this problem. To investigate the direct and residual effect of sub-soiling on soil physical properties and productivity of cotton-wheat cropping system, we conducted a field experiment for three cropping cycles (2014-2017) at two different sites and evaluated a total of five treatments (Control, Sub-soiling at 1.0 m, Sub-soiling at 1.5 m, Cross Sub-soiling at 1.0 m and Cross Sub-soiling at 1.5 m) in complete randomized block design. Results elucidated that any level of sub-soiling if applied once, improved the infiltration rate besides reduction in the bulk density for two years. Consequently, higher root length and increased root mass of cotton under sub-soiled treatments revealed advantages by improvement in yield attributes and seed cotton. Cotton sown after sub-soiling recorded significantly higher seed cotton yield while control exhibited statistically least for two years. Sub-soiling applied prior to cotton sowing in initial year also had beneficial residual effect on succeeding wheat for subsequent two crop cycles. However, during third year, at par yield levels among studied treatments for both the crops indicated that residual effect of sub-soiling persisted no longer beyond two years. Better economic returns and consequently improved benefit: cost ratio clearly revealed that sub-soiling has economic benefits. Our studies concluded that sub-soiling exerted beneficial effect on soil physical properties by reduction in bulk density and improved infiltration rate and any sub-soiling either at 1.0 or 1.5 m once in three years has potential for improving productivity of cotton-wheat cropping system occupying 1.2 million ha in North-Western India.

Biomass densification: Effect of cow dung on the physicochemical properties of wheat straw and rice husk based biomass pellets

This study investigates the potential of cow dung, an animal manure, as a binder to enhance the physicochemical properties of the base pellet (a mixture of wheat straw and rice husk). In the first step, preliminary experiments were performed to select the best composition of wheat straw and rice husk for the base pellet. The selection was based on calorific value. Subsequently, the effect of operating parameters such as varying compositions of cow dung (0–100%), molasses concentration (0–100%) and drying time (12–48 h) was investigated. Thus, Central Composite Design using Response Surface Methodology was used to investigate the proximate analysis, calorific value, bulk density and durability of biomass pellets. The experimental results suggested that the addition of cow dung into the base pellet resulted in the increase of volatile matter, ash content, bulk density and durability of the base pellet. As a result, the maximum calorific value of 14.98 MJ/kg, moisture content of 3.37%, volatile matter of 45.49%, ash content of 31.38%, bulk density of 108990 kg/m3 and durability of 95% were obtained. However, optimization of operating parameters was performed to optimize the ash percentage. With the pellet composition of 8.5% (base pellet composition of 90% wheat straw and 10% rice husk), molasses concentration of 50% and drying time of 12 h, 52% reduction in ash content and 2.3% increase in calorific value were obtained at the cost of 38% reduction in the bulk density and insignificant reduction in durability of the produced pellet. Therefore, the use of waste material like cow dung as a binder can be considered as a sustainable approach to improve the physicochemical properties especially durability of biomass pellets. Thus, it can effectively be used to fulfill the energy and heating requirement of rural areas.

Effects of Compaction at Different Soil Depths on Water Balance As Simulated by Watermod

The effect of soil compaction on water balance was investigated using the simulator Watermod. Soil samples were compressed to obtain 10% and 20% reduction in bulk density and the hydraulic conductivity was measured on the non-compacted as well as on both levels of compaction. Bundaberg climatic data together with the hydraulic conductivity values were used to run the model with all other parameters kept constant. Outputs generated by Watermod revealed that ground evaporation and total evapotranspiration decrease with higher levels of compaction as a result of an alteration of the soil water storage capacity. Runoff also increases with compaction levels as a consequence of reduced soil porosity, pore numbers and hydraulic conductivity. It was found that soil drainage is inversely related to runoff, as compaction decreases soil drainage. Two main factors - the silty texture of the soil and the poor distribution of rainfall over the year - could explain this soil drainage reduction. The relatively high content of organic matter in the soil buffered the damaging effects of moderate levels of compaction. This study builds confidence in the accuracy of Watermod simulations as its results confirmed field experimental data. Furthermore, it highlights the need for improved soil management to avoid or limit soil compaction.

Cover Crops and Returning Residue Impact on Soil Organic Carbon, Bulk Density, Penetration Resistance, Water Retention, Infiltration, and Soybean Yield

Core IdeasResidue returned increased organic carbon and reduced bulk density compared to residue not returned.Residue returned increased water retention and infiltration compared to residue not returned.Residue returned and cover crop increased soil volumetric water content and water storage.Cover crop reduced bulk density and increased water infiltration compared with no cover crop.Cover crop increased the soybean yield by 14% compared with no cover crop.Residue management with cover crops (CC) can conserve soil moisture and thus has a potential to increase crop yield, but its effectiveness varies significantly by region and cropping system management. A study was conducted at Brookings, SD, on fine‐silty, mixed, superactive, frigid, Calcic/Pachic Hapludolls soils to understand the impact of CC and crop residue on soil properties and soil‐water dynamics for soybean (Glycine maxL.) crop grown after corn (Zea maysL.). The site had two crop residue treatments (residue returned [RR] and residue not returned [RNR]) under a no‐till corn–soybean rotation. Each residue returned treatment was later subdivided to include CC and no CC (NCC) treatments. Results from this 3 yr (2014, 2015, and 2016) study showed that RR (1.30 Mg m–3) had 7% lower bulk density (BD) compared to the RNR (1.40 Mg m–3). Soil organic carbon (SOC) was 22% higher under RR (26.2 g kg–1) compared to RNR (21.5 g kg–1). Soil water infiltration was 66% higher under RR (108 mm h–1) compared to RNR (64.8 mm h–1). Similarly, soil water infiltration in CC treatment (111 mm h–1) was 80% higher compared to NCC (61.7 mm h–1). The RR with CC treatment increased soil volumetric water content and soil water storage. Overall, the CC increased soybean yield by 14% compared to NCC. Data from this study suggest that the use of CC with RR are beneficial for improving soil properties, conserving soil moisture and enhancing crop yield.

Physico-functional, thermo-pasting and antioxidant properties of microwave roasted sorghum [Sorghum bicolor (L.) Moench

The present study investigated the effects of microwave roasting on physical, thermal, functional, pasting and antioxidant properties of sorghum. The results demonstrate a significant (p < 0.05) reduction in sorghum bulk density upon roasting (778–546 kg/m3). Roasting increased the total colour change and browning index from 14.8 to 48.2 and 17.9 to 64.8, respectively, but decreased the lightness ‘L*’ from 83.1 to 50.6. Onset temperature, peak temperature, and end temperature for the amylose-lipid complex decreased by 21.00%, 19.01%, and 17.03%, respectively. Similarly, peak viscosity, pasting viscosity, breakdown viscosity and setback from the trough decreased from 2295 to 35.42, from 26.15 to 16.67, from 984.8 to 8.38 and from 2013 to 17.97, respectively. Non-significant variations in starch gelatinization and functional properties were observed. However, roasting had significant effects on total phenolic content, total flavonoid content and antioxidant properties of sorghum flour changing the corresponding values from 2.64 to 4.67 mg GAE/100 g, from 3.89 to 2.73 mg QE/100 g and from 92.50 to 83.95% DPPH, respectively. Roasted sorghum flour with better functional, pasting and antioxidant properties can be used for the development of various functional and healthy bakery products, which are especially suitable for consumption by the celiac disease population.

ORGANIC CARBON, NITROGEN AND THE STABILITY OF SOIL AGGREGATES IN AREAS CONVERTED FROM SUGAR CANE TO EUCALYPTUS IN THE STATE OF ALAGOAS

ABSTRACT The conversion of areas cultivated with sugarcane into eucalyptus forests can promote improvements in the physical, chemical and biological properties of the soil. Within this context, the aim of this study was to evaluate the changes in the stocks and levels of carbon and nitrogen and soil-aggregate stability in an area of transition from sugarcane to eucalyptus in the State of Alagoas, Brazil. The study was carried out on a rural property, located in the district of Atalaia. The systems under evaluation consisted of four areas, one cultivated with sugarcane for approximately 20 years, taken as the reference area for the study, and three adjacent areas cultivated with eucalyptus forest, at 1, 3 and 6 years of age. Bulk density, the levels and stocks of carbon and nitrogen, and the soil aggregation index were all determined. The conversion of a sugarcane plantation under conventional tillage with straw burning into eucalyptus plantations promoted an increase in the levels and stocks of carbon and nitrogen in the soil; it also reduced bulk density and increased the water stability of aggregates. The results show that the conversion of sugarcane into eucalyptus in the Atlantic Forest region of Alagoas may be an alternative for promoting carbon sequestration and improving soil quality.

Optimum Weed Control Method Increases the Yield of Kinnow by Improving the Physical Properties of Soil

ABSTRACT: Going towards sustainable fruit culture, it is very important that soil fertility should maintain by adopting the proper weeds control and adding the organic matter. This research was carried out to identify the most suitable weed control method for Kinnow orchard. The plants of Kinnow at the age of 6 years grown under drip irrigation were selected. Weeds of orchard were managed by mulching (wood chip and black polyethylene), mechanical (cultivator and rotavator) and chemical (glyphosate) methods. Mechanical weed control was taken as control treatment. The plants where wood chip mulching was used for weed control showed maximum increase in shoot length (24.00 cm), chlorophyll contents (84.00 SPAD value) and yield (11.88 ton ha-1) followed by the plants where weeds were controlled with chemical control while lowest shoot length (12.00 and 12.33 cm), chlorophyll contents (41.00 and 42.67 SPAD value) and yield (3.80 and 4.70 ton) was achieved in cultivator and rotavator treatment respectively. Wood chip mulch also improved soil physical properties by reducing bulk density (1.49 Mg m-3), soil penetration resistance (785.33 kPa) and by enhancing soil organic matter (1.17%), hydraulic conductivity (34.50 mm/hr-1) and soil microbial biomass carbon (159.68 g kg-1) followed by glyphosate control while lowest values of soil physical properties were obtained in cultivator and rotavator weed control. Wood chip mulch also reduced weed dry weight (45.25 g) and efficiently controlled weeds (95.66%) as compared to other weed control methods. In this case, wood chip mulch performed better in all studied parameters than plastic mulch, rotavator, cultivator and glyphosate weed control. So, wood chip mulch should be recommended to citrus grower for improving soil physical properties and yield.