Acacia Angustissima Research Articles

Supplementing grass-based cattle feeds with legume leaves and its effects on manure quality and value as a soil improver for an Anthropic Ferralsol in Rwanda

AbstractCombined use of lime, animal manure and inorganic fertilisers is effective in replenishing the fertility of degraded acid soils. However, many smallholder farmers lack access to sufficient amounts of these inputs to improve the fertility and reduce the aluminium toxicity of Ferralsols. Organic manures are available but often have low nutrient content, which limits their ability to supply nutrients to soils. In a two-factor field experiment over four seasons on an Anthropic Ferralsol in Southern Province, Rwanda, we assessed (i) the effect of cattle manure on soil properties at a reduced rate affordable to smallholder farmers compared with that of NPK fertiliser applied, with and without lime also at a reduced rate, and (ii) the effect of supplementing grass in a basal cattle diet with legume leaves on manure quality and its effect on soil properties. Manure from cattle fed only the grass Chloris gayana (grass-only manure) and from cattle fed C. gayana supplemented with Acacia angustissima leaves (grass+legume manure) was applied at 5 t dry matter ha-1 (25% of the recommended rate) at the beginning of each growing season. NPK was applied as split doses supplying a total rate of 70 kg N ha-1. Lime was applied annually at a rate of 2.0 t CaO ha-1, which was 25% of the rate required to neutralise total acidity at the site. All amendments were applied only to the soil surrounding the maize plants (planting stations), which is estimated at 25% of the plot area. Maize stover was left on plots after harvest and planting stations were retained over all growing seasons. All treatments altered soil properties at the planting stations. Lime generally increased pH but there was no significant difference between lime plus manure treatments and non-limed manure treatments. Soil organic carbon concentration and cation exchange capacity were higher in manure and NPK treatments than in non-fertilised treatments. The manure treatment increased soil water-holding capacity compared with the NPK and non-fertilised treatments. There was no significant difference in total N, Ca2+, Mg2+ and K+ between the NPK and manure treatments. Micro-dosing animal manure can thus replace mineral fertiliser plus lime for soil fertility replenishment in smallholder farming. Grass+legume manure contained higher concentrations of total N, Ca, Mg, K and Na than grass-only manure, but its effect on soil properties did not differ significantly from that of grass-only manure.

FEATURES OF ORGANOCHLORINE PESTICIDES RESIDUES ACCUMULATION IN MELLIFEROUS PLANTS, BEE POLLEN AND HONEY

Honey is natural product, which is produced by honeybees and due to contain of minerals, vitamins, simple sugars, organic acids, antioxidants and enzymes, it is considered as product with good nutritional and therapeutic properties. All beneficial characteristics of honey are reduced if it is contaminated with extraneous chemicals include pesticides. The purpose of this research was to study pesticides residues accumulation in the flowers of different types of melliferous plants, bee pollen and honey obtained from Odessa Region during 2015–2017 years. A total of 121 samples of flowers of melliferous plants and trees, 78 samples of bee pollen and 104 samples of honey were investigated with gas-liquid chromatography method. We found that all investigated samples were positive to such organochlorine pesticides as α, β, γ–isomers of hexachlorocyclohexane and dichlorodiphenyltrichloromethylmethane and its derivatives in different concentration. Our studies determined that high level of organochlorine pesticides was in samples of sunflower flowers whith average concentrations of α, β, γ–isomers of hexachlorocyclohexane 7.51±0.04 μg/kg, and DDT 6.98±0.02 μg/kg. Flowers of buckwheat and others field herbs (including as wild herbs as fodder crops) had even less concentration of these pesticides. Besides, the obtained results show that in the flowers of fruit trees (cherry, apple, pear, cherry, peach, cherry plum) had less concentration of studied pesticides in compere to forest trees (white acacia, linden). The results of bee pollen and honey samples examination have shown the same situation. The highest concentration of α, β, γ–isomers of hexachlorocyclohexane and dichlorodiphenyltrichloromethylmethane was in sample from sunflower origine with average consentration 3.52±0.05 and 3.77±0.03 μg/kg in bee pollen, 2.74±0.01 and 2.53±0.03μg/kg in honey respectively. However, the detected concentrations of pesticide residues in all samples were lower than the maxim admissibile limits, according to national and EU standards. Despite this, we suggest that regularly monitoring of pesticide residues in melliferous plants and apiculture products at national level need to grantee of quality and safety of honey and protection of consumers` health.

Differentiation of Omani Acacia and white Acacia honey by botanical and physicochemical analysis

Differentiation of Omani Acacia and white Acacia honey by botanical and physicochemical analysis

Features of the structural-aggregate composition of ordinary chernozems under the steppe and forest vegetation

The structural-aggregate composition is an important soil characteristic, which reflects the features of the genesis, condition and regimes of soils. The structural and aggregate composition of ordinary chernozems under zonal steppe vegetation and under artificial forest plantations from white acacia and common oak in the conditions of the Prisamaría was studied. As a result, it was found that in all the studied soils the greatest content falls on the fraction 2–1 mm in size. In ordinary chernozems in the upper horizons, under the stands of white acacia and common oak, an increase in the content of this agronomically valuable fraction is observed. Also in ordinary chernozem under forest stands, an increase in the value of the structural coefficient is observed compared with ordinary chernozem under steppe vegetation. In ordinary chernozem the most favorable effect of the growth of white acacia was found in horizon H, and the growth of ordinary oak in horizon H2, in which the highest values ​​of the structural coefficient were found. In the studied ordinary chernozems under the steppe and forest vegetation a predominance of the water-resistant fraction of size <0.25 mm is observed. The positive effect of white acacia and common oak plantations on the water resistance of aggregates of common chernozem in the upper horizons is manifested in a decrease in the content of the fraction of size <0.25 mm compared to ordinary chernozem. In ordinary chernozems under steppe vegetation the most favorable conditions for the formation of agronomically valuable fractions during dry sieving are characteristic of the lower horizons and for chernozems under forest stands in the upper horizons. In all the studied soils the highest content of agronomically valuable fractions during wet sieving was found in the upper horizons, but there are more of them in chernozems under forest stands. The highest content of agronomically valuable fractions in all studied soils is observed in the lower horizons and their highest content in the upper horizons is found in ordinary chernozems under the steppe vegetation. The highest values ​​of the water resistance criterion are characteristic of the lower horizons of the studied chernozems. The maximum values ​​of this criterion were found in ordinary chernozem under oak plantation, and the smallest – under acacia plantation. The growth of forest plantations on ordinary chernozems leads to an improvement in their structural-aggregate composition.

Serum metabolites and weights of internal organs of broilers fed on varying levels ofAcacia angustissimaleaf meal

The objective of this study was to determine the relationship between inclusion levels of Acacia angustissima leaf meal against nutritionally related blood metabolites, activity of liver enzymes, a...

Response of broiler (Gallus gallus domesticus) performance and carcass traits to increasing levels of Acacia angustissima leaf meal as a partial replacement of standard protein sources

SUMMARY Important raw material incorporated in feed formulation for poultry is expensive, thus hindering the growth of the poultry industry in tropical regions. Therefore, the authors investigated the effect of including different levels of Acacia angustissima leaf meal in the diet of broilers (as an alternate protein source/cereal grain ingredient) on growth performance and carcass yield. A total of 160 Ross 308 broiler chicks weighing 0.90 ± 0.043 kg was assigned to 6 treatment diets of 0, 30, 60, 90, 120, and 150 g/kg DM, in a completely randomized design. Each treatment was replicated 4 times. The experimental period of lasted for 35 d inclusive of environmental and diet adaptation. The results indicated a quadratic decrease on final body weight (FBWT) (P

БІОЕКОЛОГІЧНИЙ АНАЛІЗ ФЛОРИ БІОТОПУ ЗАЛІЗНИЦЬ м. ДНІПРО

Наведено біоекологічний аналіз флори та аналіз адвентивної фракції біотопу залізниць м. Дніпро. Список флори складено на основі власних польових досліджень. Флора залізниць м. Дніпро представлена 167 видами судинних рослин, які належать до 42 родин та 138 родів. Адвентивна фракція флори представлена 47 видами судинних рослин.

ENSAYO DE LEGUMINOSAS PARA LA REFORESTACIÓN DE LA 2a SECCIÓN DEL BOSQUE DE CHAPULTEPEC


 
 
 La Segunda Sección del Bosque de Chapultepec es un sitio de preservación ecológica, generación de servicios ambientales y de beneficios recreativos, principalmente, para los habitantes de la Ciudad de México. En los últimos años se ha registrado una declinación y disminución de su cubierta forestal, por lo que es necesario llevar a cabo programas de reforestación que se realicen con las especies apropiadas al sitio. Se realizó un ensayo de seis leguminosas arbóreas con el objetivo de evaluar su supervivencia y tasas de crecimiento en altura y diámetro basal; en el primer rubro, el valor final fue de 100 a 92.59%, en función de la especie, aunque no hubo diferencias significativas entre ellas. La tasa de crecimiento en altura fue mayor y significativamente diferente en Albizzia occidentalis y Senna multiglandulosa, respecto a los otros taxa; mientras que la correspondiente al diámetro resultó superior en S. multiglandulosa, Acacia angustissima y A. occidentalis. En contraste, Leucaena esculenta presentó las cifras más bajas en ambas variables, pero no difirió significativamente de Eysenhardtia polystachya, ni de Lysiloma divaricata. En algunas plantas se registraron daños por vandalismo, así como por el ataque de plagas. A pesar de ello, los resultados permiten afirmar que estas son una buena opción para la reforestación del área de estudio, lo que confirma la importancia de realizar ensayos de especies previos a los programas de reforestación urbana.
 
 

Relationships between Structures of Condensed Tannins from Texas Legumes and Methane Production During In Vitro Rumen Digestion.

Previous studies showed that a series of purified condensed tannins (CTs) from warm-season perennial legumes exhibited high variability in their modulation of methane production during in vitro rumen digestion. The molecular weight differences between these CTs did not provide correlation with either the in vitro CH4 production or the ability to precipitate bovine serum albumin. In an effort to delineate other structure-activity relationships from these methane abatement experiments, the structures of purified CTs from these legumes were assessed with a combination of methanolysis, quantitative thiolysis, 1H-13C HSQC NMR spectroscopy and ultrahigh-resolution MALDI-TOF MS. The composition of these CTs is very diverse: procyanidin/prodelphinidin (PC/PD) ratios ranged from 98/2 to 2/98; cis/trans ratios ranged from 98/2 to 34/66; mean degrees of polymerization ranged from 6 to 39; and % galloylation ranged from 0 to 75%. No strong correlation was observed between methane production and the protein precipitation capabilities of the CT towards three different proteins (BSA, lysozyme, and alfalfa leaf protein) at ruminal pH. However, a strong non-linear correlation was observed for the inhibition of methane production versus the antioxidant activity in plant sample containing typical PC- and PD-type CTs. The modulation of methane production could not be correlated to the CT structure (PC/PD or cis/trans ratios and extent of galloylation). The most active plant in methane abatement was Acacia angustissima, which contained CT, presenting an unusual challenge as it was resistant to standard thiolytic degradation conditions and exhibited an atypical set of cross-peak signals in the 2D NMR. The MALDI analysis supported a 5-deoxy flavan-3-ol-based structure for the CT from this plant.

English

This study investigated the effect of cutting height (30 and 100 cm) on chemical composition and in vitro digestibility in field-grown Acacia angustissima (Mill.) Kuntze. (Prairie acacia), Leucaena pallida Britton & Rose (guaja) and Mimosa scabrella Bentham. (bracatinga) legumes and their value in supplementing a basal diet of Chloris gayana Kunth. (Rhodes grass). Cutting height did not affect major chemical composition. Crude protein (CP) was highest in A. angustissima and lowest in M. scabrella, while neutral detergent fibre (NDF) and acid detergent fibre (ADF) were highest in M. scabrella. Degradation parameters were greater at 100 cm cutting height. L. pallida showed high in vitro organic matter digestibility but A. angustissima had the highest metabolisable energy. Addition of A. angustissima, L. pallida and M. scabrella to the basal diet increased improved the nutritional value and increased the CP content from 8.4 to 19.8% and 18.1 and 16.1%, respectively. Cutting height of A. angustissima, L. pallida and M. scabrella had no effect on their nutritional value. Their other functions and benefits will determine choice of cutting height as management practice when used on farms. Key words: Legume trees, cutting height, chemical composition, in vitro degradability. &nbsp

ОСОБЕННОСТИ ЭКОЛОГИИ TORTRIX VIRIDANA L. В УСЛОВИИИ ЦЕНТРАЛЬНОЙ ЛЕСОСТЕПИ

Green oak tortrix (Tortrix viridana L.) occupies a leading position in the leaf-biting pests of English oak (Querqus robur L.). Full-scale research on permanent test plots in the oak groves of the Voronezh Region and laboratory experiments at the Department of Ecology of VSUFT has revealed that the exit of the larvae of green oak tortrix is synchronized with the opening of the buds of the early form of the oak tree, and larvae have a regional specificity. Caterpillars of the first ages of green oak tortrix both in field and laboratory conditions show themselves as strict monophages, and caterpillars of the 5th age are facultative polyphages. For normal hatching of larvae, reactivation with low temperatures is necessary, followed by a set of effective temperatures of more than 1,750 ° C. At the same time, temperatures below -30 ° C for 3 days or spring frosts below -60 ° C lead to the death of oviposition. The speed of movement of the newly born caterpillars of green oak tortrix is 16 cm per minute or 9.6 m per hour, that is, during the active period, the newly born caterpillar can overcome 30-60 meters in search of food. The range of variation in the width of the head capsules of larvae of all 5 ages has been determined. The duration of the period of pre-fast fasting and sleep in older caterpillars varies considerably (2 = 0.709)but has a rather close correlation with the absolute weight of caterpillars (r = 0.587). The duration of the pupal stage is 7-13 days. In laboratory conditions, at a temperature of 220 ° C, the first butterflies fly out after 5 days. In nature, the flight of butterflies coincides with the flowering of jasmine, white acacia, black elderberry. The first males fly out and the females fly out only after 2-3 days. Mass flying begins 4-5 days after the appearance of the first butterflies. The butterflies’ outflying lasts 8-12 days, and they can be found in plantation for 16-28 days. From the entomophages of green oak tortrix, riders Phytodietus polizonias Forst., and on the puppies Phaeogenes invisor Thunb. Apechtis rufata Gm. Hoplectis maculator F. has been noted. The tahin Elodia tragica has been also found on the pupae. Trichogramma evanescens Weit. and Trihogramma embryophagum Htg. have been noted as the main ovaries of green oak tortrix

Effect of <i>Acacia angustissima</i> leaf meal on performance, yield of carcass components and meat quality of broilers

The study determined the appropriate levels of including Acacia angustissima leaf meal in broiler diets for optimum performance, carcass part yield, and meat quality characteristics. One hundred and fifty broiler chicks were allocated to 0%, 5%, and 10% A. angustissima leaf meal-based diets in a completely randomized design, with five replicates per treatment. Weekly feed intake and live weights were measured. Weekly weight gains and feed conversion ratios were calculated. At six weeks, two birds per replicate were slaughtered and dressed. Carcass and portion yields were determined. Breast proximate components, CIELAB colour variations, cooking loss and shear force were estimated. Consumer preferences for colour, aroma, taste, flavour and tenderness were determined. Voluntary feed intake (VFI), weekly weight gain, weekly live weights and feed conversion ratios (FCR) were the same across treatments at two weeks. At weeks 4 and 6, the control and 5% groups outperformed the 10% group. Increasing dietary leaf meal had no effect on dressing out percentage, but decreased carcass weight from 1456 g to 1060 g, breast yield from 36.83% to 32.69%, breast meat to bone ratio from 4.77% to 2.94%, and proportion of drumstick skin from 11.57% to 7.92%. It also resulted in increased yield of thighs from 14.63% to 15.97%, proportion of thigh skin from 11.50% to 14.31% and breast skin proportion from 5.37% to 7.95%. The leaf meal had no effect on the proximate components of breast meat. The L* values decreased from 53.66 to 49.23; the b* values increased from 12.93 to 19.97; shear force increased from 14.14 N to 14.54 N; and cooking loss increased from 5.95% to 7.64% with increasing leaf meal levels. It was concluded that up to 5% A. angustissima leaf meal inclusion has no negative effect on performance, yield of carcass parts and meat quality characteristics of broilers. Keywords: Breast, colour, cooking loss, shear force, taste

Serum lipid, enzyme, and hematological responses of broilers fed Acacia angustissima leaf meal-based diets.

The objective of the study was to determine serum lipid, enzyme, and hematological responses of broilers to Acacia angustissima leaf meal. Acacia angustissima leaves were harvested at mid maturity, ground into a leaf meal, and included in broiler diets at 0, 5, and 10%. One hundred and fifty-day-old chicks of 41.7 ± 1.560g were randomly allocated to 15 groups of the three diets. Feed and water were provided ad libitum throughout the trial. At days 14, 28, and 42, 4ml of blood were collected from the jugular vein in plain vacutainer tubes for alanine aminotransferase (ALT), alkaline phosphatase (ALP), aspartate aminotransferase (AST), lactate dehydrogenase (LDH), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), and total cholesterol (TC) analyses. At the end of the experiment, 4ml of blood were collected from two randomly selected birds of each replicate in sterilized bottles containing ethylene diamine tetra acetic acid (EDTA) for full blood count and packed cell volume assessment. Data was tested for normality and analyzed using the General Linear Model Procedure of SAS version 9.3 (SAS 2010). Comparison of means was done using Tukey's test. A. angustissima had no effect on serum ALP, AST, LDH, TC, HDL-C, LDL-C, TG, full blood count, and packed cell volume. Increasing levels of A. angustissima leaf meal increased the ALT in the serum (p <0.05) at 4 and 6weeks. However, serum ALT indices for birds on the control and 5% diet were not different. It was concluded that 5% A. angustissima leaf meal can be included in broiler diets without a negative effect on serum lipid and enzyme profile, production and proportions of white blood cells and packed cell volume.

Effect of Acacia angustissima Leaf Meal on the Physiology of Broiler Intestines

The effect of A. angustissima leaf meal based diets on intestinal physiology and dressed carcass weight was investigated on 150 day old chicks. Three diets, 0, 5 and 10% A. angustissima were used in a three phase feeding programme. At days 14, 28 and 42, two birds from each replicate were slaughtered, dressed and weighed. The weights and lengths of the duodenum, jejunum and colon were measured. Approximately 1 cm specimen was taken from each organ, fixed in formalin and stained for histological analysis. Using a light microscopy, the digestive and absorptive properties of the tissues were assessed. Inclusion of A. angustissima leaf meal increased intestinal wall thickness, epithelial thickness, and villus height of the duodenum (P &lt; 0.05). There was no effect on the proportional weight and length of the jejunum, jejunum villi height and villi width (P &gt; 0.05) but jejunum wall thickness decreased with increasing levels of the leaf meal (P &lt; 0.05). Leaf meal inclusion resulted in an increase in weight, intestinal wall and mucosal thickness of the colon (P &lt; 0.05) and a decline in sub-mucosal fold height and haustra coli width of the colon (P &lt; 0.05). Dressed weight was the same across diets at two weeks (P &gt; 0.05). At four and six weeks, broilers on the control and 5% diet had superior dressed weights to the 10% fed broilers (P &lt; 0.05). It was concluded that for intestinal physiological adaptation that will not compromise weight gain in broilers, up to 5% A. angustissima could be included in broiler diets.

The effectiveness of heating of housing unit by renewable energy source

The paper is aimed at pointing out possibilities of using of dendromass for heating. The object of interest was heating of housing units with 75.27 m&lt;sup&gt;2&lt;/sup&gt; of total area. The average value of dendromass moisture was 17.71%. The inserted fireplace Nordica Focolare 70 with a nominal output of 9 kW was used as a heat source. For temperature measurement, a non-contact infrared thermometer GM 900 was used. The total heat loss transferred through walls of housing unit (heat loss through thermal bridges and ventilation losses) were calculated at the value of 176.26 W/K. Based on the results of samples moisture the net calorific value of one kilogram of burned fuel wood was determined (14.791 MJ kg). The amount of thermal energy which is necessary to supply by the heating system for the whole heating period was 14,199.18 kWh. The weight of raw fuel wood was 5,450.97 kg (at moisture of 30%), dried at 17.71% (4,636.87 kg). Price of raw fuel wood of acacia for the year under evaluation was 64.80 €/m&lt;sup&gt;3&lt;/sup&gt; (the required amount of raw fuel wood for heating period was 10 m&lt;sup&gt;3&lt;/sup&gt;). Total costs for the heating season was thus 648 €. The price of heat transmitted by the fireplace inset Nordica Focolare 70 inserted into heating system using fuel wood (white acacia) with 17.71% of absolute moisture was 0.045636 €/kWh.

Перспективи відтворення та рекреаційного використання порушених земель внаслідок сірчаних розробок (на прикладі території Яворівського сірчаного кар’єру)

Охарактеризовано основні стадії формування території Яворівського сірчаного кар’єру та виділено кілька видів панівних ландшафтів. Проведено соціологічне опитування респондентів шляхом анкетування щодо облаштування та ревіталізації території навколо кар’єру шляхом створення рекреаційних об’єктів. Здійснено аналіз основних напрямків створення рекреаційної зони на досліджуваній території. На основі статистичних даних динаміки розвитку Яворівського району, проведено оцінку сучасного стану окремих показників діяльності. На підставі отриманих результатів запропоновано систему заходів щодо відновлення порушених земель, покращення екологічної ситуації на цій території та формування сприятливого інвестиційного клімату для створення відпочинкових і спортивно-оздоровчих комплексів на території аналізованого об’єкта. Запропоновано зосередити особливу увагу на створенні в межах порушених ландшафтів лісових масивів, парків і лісопарків.

DECOMPOSIÇÃO DAS PODAS DAS LEGUMINOSAS ARBÓREAS &lt;i&gt;Gliricidia sepium &lt;/i&gt;E &lt;i&gt;Acacia angustissima &lt;/i&gt;EM UM SISTEMA AGROFLORESTAL

http://dx.doi.org/10.5902/1980509819696Os Sistemas Agroflorestais (SAFs) trazem benefícios múltiplos e constituem uma alternativa para minimizar a degradação ambiental e alcançar um desenvolvimento sustentável, devido à diversidade de espécies que os compõe. O presente estudo avaliou a contribuição das leguminosas arbóreas, Gliricidia sepium e Acacia angustissima, cultivadas em aleias intercaladas com banana (Musa sp.) e açaí (Euterpe oleraceae), na implantação de Sistema Agroflorestal. Comparou-se a produção de biomassa e ciclagem de nutrientes no SAF, com a leguminosa herbácea Pueraria phaseoloides e adubação nitrogenada. O SAF foi implantado em maio de 2004, no Campo Experimental da Embrapa Agrobiologia, em Seropédica - RJ. O delineamento experimental foi de blocos casualizados com cinco tratamentos, constituídos das leguminosas acácia-angustíssima (Acacia angustissima), kudzu-tropical (Pueraria phaseoloides), gliricídia (Gliricidia sepium) dispostas nas entrelinhas da banana e do açaí; além de adubação nitrogenada com ureia, e cobertura viva oriunda da vegetação espontânea. Para quantificar a produção de biomassa e liberação de N, P, Ca, Mg e K in situ foram cortadas as leguminosas e roçado o kudzu-tropical e a vegetação espontânea. As determinações da matéria seca remanescente, liberação de nutrientes, constantes de decomposição e os tempos de meia-vida dos resíduos vegetais foram realizadas acondicionando-se 50 g de material fresco em litterbags, dispostos na superfície do solo, tomando-se amostras aos 0, 5, 10, 15, 20, 25, 30, 40, 60 e 75 após o início do experimento. Acacia angustissima e kudzu-tropical apresentaram maior produção de biomassa seca, igual a 10,8 Mg ha-1. Os resíduos da gliricídia resultaram em maiores constantes de decomposição, nas duas estações do ano.

YIELD AND NITROGEN RECOVERY OF RAPE (BRASSICA NAPUS L.) IN RESPONSE TO APPLICATION OF LEGUMINOUS LEAF LITTER AND SUPPLEMENTAL INORGANIC NITROGEN

SUMMARYThe short term nutrient supply of Leucaena leucocephala, Calliandra calothyrsus, Acacia angustissima and Acacia karoo prunings with or without supplemental inorganic nitrogen were tested using rape (Brassica napus L.) in a field trial. Prunings were applied at a rate of 5 t ha−1 to soil, alone or with supplemental N at 37.5 kg N ha−1 (¼ of recommended N). The respective decomposition and N release constants of the prunings were 9.15 and 9.70% for L. leucocephala; 6.15 and 6.40 for A. angustissima; 4.50 and 4.90 for C. calothyrsus; and 2.20 and 2.10 for A. karoo. These constants were best described by the (lignin+polyphenol)-to-nitrogen ratio of the prunings. Total biomass over the two seasons ranged from 1.40 to 17.28 t DM ha−1 and total growth rates ranged from 2.34–26.70 g plant−1 week−1. The cumulative N recovery at week 9 ranged from 21.1–66.1 %. Legume tree leaves can be used as a source of N for vegetable production. Farmers who use high tannin leaf litter are recommended to supplement with mineral N in order to assure adequate N availability during plant growth.

Effects of reforestation on degraded soils in the moist semi deciduous zone of West Africa

Reforestation with trees and shrubs may be an effective means of increasing soil organic matter content and for regeneration of degraded lands. A study was conducted on a degraded farmland Chromic Luvisol (UNESCO/FAO) or Udic Rhodustalf (USDA, 1999) in the moist semi deciduous zone of West Africa, near Onwe, located at latitude 06 o 41’ N, longitude 01 o 28’ W, and at an altitude of 305m asl. The objective of the study was to quantify the improvement in soil physicochemical properties of degraded Chromic Luvisol with exotic leguminous tree species compared to grass vegetation in the moist semi-deciduous zone of West Africa. To quantify changes due to reforestation, we measured some physical and chemical properties of soil after 20 years (1989 – 2009) of reforestation with Acacia angustissima (Acacia), Cassia siamea (Cassia), and Leucaena leucocephala (Leucaena) mixed and compared with soils under natural grass vegetation. Experimental design used for soil sampling and for evaluating the soil properties was randomized complete block with three replications. Soil organic matter increased from 1.19% to 2.02% while pH dropped from 5.65 to 4.79 in the reforested soils. Cumulative infiltration, infiltration rate, and gravimetric water content showed significant improvement under reforestation compared with soils under natural vegetation. Total porosity increased from 36.7% in the natural grass cover to 51.3% in the reforested soils. Reforestation resulted in significant reduction in bulk density from 1.67 to 1.26g/cm 3 . Improvement of soil properties under reforestation indicates that planting of well-adapted and fast-growing exotic tree species can gradually improve soil quality and regenerate degraded lands. Reforestation may be thus recommended as a way of regenerating degraded land. Keywords : Degraded soil, reforestation, trees, soil organic matter

IMPACTO DE LA PENDIENTE Y TRES SISTEMAS DE PRODUCCIÓN SOBRE EL ESCURRIMIENTO, LA EROSIÓN Y EL RENDIMIENTO DE MAÍZ

&lt;p&gt;In2001 aresearch work was carried out in Suchiapa, Chis., Mexico, in order to diagnose the level of fertility of hillside soils, in six strata formed by three slope ranges and two management systems, as well as to evaluate the impact of the slope and three production systems on soil runoff and erosion, and corn yield. The model EPIC (Erosion/Productivity Impact Calculator) was fed with information obtained from soils analyses, climate, soil management the corn crop data, to perform simulations for nine scenarios formed by three ranges of slope (&amp;lt;5, 5-15 and &amp;gt;5%) and three types of land use (corn planting, corn planting intercropped with contour hedgerows of prairie acacia and commercial planting of prairie acacia), to estimate their impact on runoff, erosion and corn yield. There were significant differences in the slope and land use factors in all soil characteristics evaluated, but in the interaction of both factors, only significant differences (P≤0.01) in the cation exchange capacity and the organic carbon were detected. In the evaluation of the effect of slope and production systems, significance (P≤0.01) was only detected in the land use factor, in the runoff and erosion variables.&lt;/p&gt;