Effects Of Different Management Systems Research Articles

Soil Water in Different Management Systems of Coffee-Pine Agroforestry and Its Relation to Coffee Bean Yields

Coffee-pine agroforestry is a common land use system in Indonesia, that provides several benefits, including increased soil fertility, biodiversity, and economic returns. However, the management of coffee-pine agroforestry systems can significantly impact on soil water dynamics, affecting coffee bean yields. This study investigated the effects of different management systems on soil water dynamics and coffee bean yields in a coffee-pine agroforestry system in UB Forest, Malang East Java, Indonesia. Five different management systems were evaluated: (i) no management, (ii) pruned coffee with no fertilizer, (iii) pruned coffee with added organic fertilizer, (iv) pruned coffee with added organic-inorganic mix fertilizer, with a planting distance of pine trees of 3 x 2 m, and (v) pruned coffee with added organic-inorganic mix fertilizer under pine trees with a planting distance of 6 x 2 m. The soil water dynamics were measured at depths of 0-0.2 m with a soil moisture sensor and connected with a data logger measured within a year, started in April 2022. Coffee bean yield was measured with 100 coffee plants, then converted to production on ton ha−1. The results showed that the different management systems significantly impacted soil water dynamics and coffee bean yields. The combination of pruning and fertilization is a promising management strategy for increasing coffee bean yields in coffee-pine agroforestry systems. The consequent better growth of coffee plants impacts increasing soil water extraction. This study provides valuable insights for farmers and forest managers who are interested in improving the productivity of coffee-pine agroforestry systems and conserving soil water or sometimes needing water addition through irrigation.

The Effect of Different Management Systems and Racing on the Stress Level of Arabian Horses

The Effect of Different Management Systems and Racing on the Stress Level of Arabian Horses

The effect of different management systems on milk yield and milk quality in Awassi sheep.

This study aimed to evaluate the effect of concentrate-based feeding (CF) and artificial pasture-based grazing (APG) management systems on milk yield, fatty acids, nutritional indices, and milk physicochemical characteristics of Awassi ewes. The research involved 300 heads of Awassi ewes, which were divided into two groups. Awassi sheep were managed in a CF and APG system to test the milk yield characteristics. The results showed a significant ( ) difference in milk yield and lactation length between CF and APG management systems of ewes. The average daily milk yield showed a nonsignificant difference for both management systems, and no significant changes ( ) in the chemical composition of CF and APG management systems were observed. Palmitic (C16:0), myristic (C14:0), stearic (C18:0) capric (C10:0), and lauric (C12:0) acids were the major saturated fatty acids found in milk from both management systems. The level of linoleic acid (C18:2 n-6) was significantly different in both treatments ( ), but the linolenic (C18:3 n-3) acid level was nonsignificant in milk from the CF and APG management systems. The hypocholesterolemic / hypercholesterolemic (h / H) fatty acid and thrombogenicity (TI) ratios were significantly different ( ); however, the atherogenicity (AI) had no significant difference between confined and grazing systems. In conclusion, it can be said that the lactation length and lactation milk yield were prolonged by the APG management system, though the milk composition and quality were not significantly affected.

Effect of Different Management Systems on Growth and Carcass traits of Post Weaned Male Kachhi Lambs

Effect of Different Management Systems on Growth and Carcass traits of Post Weaned Male Kachhi Lambs

Blood biochemical metabolites of Post-Parturient goats under different management systems in Himalayan Region

A study was conducted to evaluate the effect of different management systems on the blood biochemical metabolites of post-parturient crossbred goats (Boer x Bhakarwal) during winter season (January to March, 2017) in Kashmir valley. Thirty healthy post-partum does were randomly divided into five groups (G1 to G5) of six animals each with similar weight and parity. G1 (control) was reared inside the shed and G5 in open and both the groups were neither provided any bedding material nor were they offered any additional concentrate supplement. Groups G2, G3 and G4 were kept inside the shed during the study period. G2 was provided with a straw bedding of 5 cm thickness and no additional concentrate supplement. G3 was supplemented with additional pelleted concentrate feed @ 100 g/head/day but no straw bedding. G4 was provided both straw bedding of 5 cm thickness and additional pelleted concentrate feed @ 100 g/head/day during the study period. The results indicated that minimum temperature during the study period ranged from-2.50±0.38oC to 3.23±0.61oC in the open shed and 4.83±0.41oC to 10.13±0.68oC inside the shed with lowest thermal humidity index (28.30±0.54) in January in open shed. Blood glucose, triiodothyronine (T3), thyroxine (T4) hormones were significantly (P<0.05) higher in group (G5) kept outside as compared to other groups (G1 to G4) at the final stage of the experiment. Highest levels of total protein (6.53±0.12 g/dl) and triglycerides (29.33±0.91 mg/dl) were found in G4 at the end of the trial. It can be concluded that goats are susceptible to cold and may be protected from cold by providing concentrate supplementation to combat stress during peak winter months when temperature dips below zero in Kashmir valley.

Long-term effect of early nutrition on endocrine parameters and liver and endometrial gene expression of the members of the somatotrophic axis in Hereford heifers.

This study compared the effect of different management systems on endocrine parameters, and gene expression of members of the somatotrophic axis in the liver and endometrium of beef heifers. Twenty-two 709-days-old heifers submitted to Early Weaning (EW, n=8), Traditional Weaning (TW, n=7) and TW plus creep feeding (TW+CF, n=7) were used. Animals were synchronized with two prostaglandin (PG) injections at 11-day interval (Oestrus=Day 0). Blood samples were collected daily for progesterone (P4) determination, and endometrial and liver biopsies on Days 7 and 16 for transcript determination of members of the somatotrophic axis. Progesterone concentrations were greater on Days 15 and 16 (p<.02) of the cycle in TW+CF than TW and EW heifers. On Day 7, TW+CF heifers expressed greater liver total growth hormone receptor transcripts than TW heifers (p=.05) and greater insulin-like growth factor (IGF)-binding protein 3 mRNA than both EW and TW groups (p<.05). On Days 7 and 16, TW+CF expressed more endometrial IGF1 mRNA than the other groups (p<.01). We conclude that increasing the plane of nutrition of nursing calves may have a long-term effect on the functioning of the somatotrophic axis both in the liver and in the endometrium.

Evaluation of two different methods to measure the effects of the management regime on the olive-canopy arthropod community

The effects of the management regime, mostly differentiated for using or not insecticides, on biodiversity have frequently been difficult to analyze and understand because of the rapid re-colonization by good-dispersers, the quick recuperation of generalists and the continuity of insecticide-resistant arthropod species. The presence of these different communities may produce values of abundance, diversity indices and species richness which do not reflect the changes caused by the impact of the insecticides in the sprayed area. In this study we assess the impact of the olive tree management on the arthropod community and the changes in this community according to the blooming season. This study has been developed in olive groves subjected to conventional and organic management regimes by two different approaches: (a) the abundance-diversity approach, measuring and comparing abundance, richness and the Shannon-Weaver diversity index (H’) of total arthropods and per guild and (b) the food-web approach, building food-webs and comparing their unweighted quantitative descriptors. We sampled the arthropods in the tree canopy in six conventional and six organic olive groves (12 plots), and in two of the periods of greatest diversity and abundance: pre-blooming and post-blooming seasons. The abundance of total arthropods, but only those within the guild of phytophagous, diminished significantly when insecticides were used. The species richness of total arthropods and specifically predators were also reduced in the conventional plots. These variables were always greater in organic olive groves. Conversely, the total and per guild Shannon-Weaver diversity index (H’) did not detect any management effect on the olive-canopy arthropod community. Furthermore, all the food-web unweighted quantitative descriptors such as size, complexity and prey-predator asymmetries showed the significant effect of the management on the olive-canopy arthropod community and also presented greater values in organic olive groves. We also found that the blooming season did not significantly change the food-web structure, contrary to what we predicted. However, predator, parasitoid and phytophagous abundance, total and predator richness were greater in the post-blooming season. This study shows that the abundance-diversity approach, and especially H’ diversity index, was not useful for describing the effect of different management systems on the canopy arthropod community. On the contrary, the food-web approach emerges as a useful tool for understanding and evaluating the ecological effect of the application of insecticides (and probably other disturbances during the management) affecting the agro-ecosystems.

Different Cover Crops Affect Nitrogen Fluxes in Mediterranean Vineyard

Core Ideas Burr medic cover crop supplied 125 kg ha–1 year–1 of fixed N to the vineyard. Twice the N needs of grapevine annual organs were satisfied by legume cover crop. Legume cover crop promoted + 25% of total N compared to grass cover crop. Compared to traditional soil tillage, the establishment of cover crops in Mediterranean vineyards has several advantages such as better soil fertility; however, vigor and N concentration of grapevine [Vitis vinifera (L.)] organs may be affected. A 3‐yr experiment was performed in Sardinia (Italy) to: (i) quantify the N fixation ability by burr medic [Medicago polymorpha (L.)] grown in a vineyard and its potential benefit for grapevines; (ii) compare the effects of different management systems (grass or legume cover crop vs. soil tillage) on grapevines. Total N fixed by burr medic was 125 kg ha−1 yr−1 and it was twice as high as the N contents of grapevine annual organs. Soil tillage promoted higher cluster and cane dry matter (+38% and +31%), compared to cover crop treatments. Legume cover crop induced higher N concentration in leaves and canes. The N content detected in grapevine annual plant growth with the legume cover crop reached 61 kg ha−1 yr−1. According to an indirect 15N dilution approach, the higher 15N enrichments detected in organs of grapevines, did not indicate that legume N was utilized by grapevine. However, lower 15N enrichment was occasionaly detected, indicating 6 and 13% of N derived from legume in clusters and canes, respectively. Compared to grapevines with grass cover, the N contribution from legume cover, estimated by the N‐difference method, induced 24, 24, and 31% of N increase in leaves, clusters, and canes, respectively. The increases corresponded to 10% of legume fixed N.

Influence of feeding, periphyton and compost application on the performances of striped grey mullet (Mugil cephalus L.) fingerlings in fertilized brackishwater ponds

To evaluate the effects of different management systems on performances of grey mullet (Mugil cephalus L.) fingerlings, a 120-day experimental trial was conducted in twelve brackishwater ponds (600m2 each). Rearing management systems assessed were: fertilization alone (FR), combined fertilization-feeding (FF), fertilization-periphyton (FP) and fertilization-compost application (FC) in triplicate ponds. Soaked mustard cake was used as a fertilizer @ 100kgha−1 at 15-day intervals in all the treatment ponds. Formulated crumble diet containing 29.7% protein and 4.9% lipid was used as a supplementary feed in FF. Bamboo poles were used as substrates (equivalent to 10% of pond surface area) to facilitate periphyton growth in FP and composted aquatic weed was applied @ 500kgha−1 in FC at monthly intervals. Ponds were stocked with grey mullet fry (3.36±0.32g/63.70±4.61mm) at 30,000numberha−1. The experiment revealed significant differences in most of the water quality parameters among the four treatments. In FP ponds, a significant reduction (P<0.05) in inorganic nitrogen and phosphorous, chlorophyll-a contents, and plankton population was observed. The highest fish growth (28.39±1.94g) and survival (94.3±4.2%) were recorded in FP followed by in FF, FC and FR (P<0.05). A significantly higher total fish biomass (P<0.05) was obtained in FP (803±29kgha−1) followed by in FF (730±37), FC (507±33) and FR (362±22). Condition factor (K) and isometric exponent (b) of length-weight relationship indicated that fingerlings were in better condition with isometric growth (K=1.37±0.13; b=3.01±0.12) in FP. Inferior condition with allometric growth was observed in FR, FF and FC systems. These results suggest that periphyton based system can be an appropriate rearing technique for grey mullet fingerling production in brackishwater fertilized ponds as an environment-friendly and sustainable practice.

Produção de amoreira-preta sob diferentes sistemas de condução

RESUMO: O objetivo do trabalho foi avaliar o efeito da produção e qualidade dos frutos de cultivares de amoreiras-pretas conduzidas em diferentes sistemas de condução. O delineamento experimental adotado foi o de blocos casualizados em parcelas subdivididas, em um fatorial 3x3. Utilizaram-se as cultivares 'Tupy', 'Guarani' e 'Xavante' e os sistemas de condução: sem tutor, espaldeira em "T" e espaldeira em fios paralelos. Avaliou-se a produção de frutas, o número médio de frutas, a massa média de frutas por planta nas safras de 2009/2010, 2010/2011 e 2011/2012. Nas duas últimas safras, também foi avaliado o conteúdo de sólidos solúveis. Os sistemas de condução influenciaram no comportamento produtivo das amoreiras-pretas, sendo que o sistema em espaldeira em "T" proporcionou maior produção e número de frutas, no entanto, a maior massa média de frutas foi obtida nas plantas conduzidas sem tutor. As plantas conduzidas em espaldeira em "T" e espaldeira apresentaram maior produção (1357,4 e 1217,8g planta-1, respectivamente) e número de frutas (341,7 e 320, respectivamente). Dentre as cultivares, a produção diferiu entre elas, destacando-se a 'Tupy' e 'Guarani' com 2098g e 2094g planta-1, respectivamente. Entretanto, o maior número de frutas por planta foi superior nas plantas de 'Guarani', sendo inversamente proporcional à massa média de frutas para esta cultivar. A cultivar 'Tupy' apresenta maior produção em relação às demais cultivares avaliadas. O número médio de frutas por planta foi superior nas plantas de 'Guarani'. Nas condições do presente trabalho conclui-se que o desempenho produtivo de amoreira-preta depende de cada cultivar e também do sistema de condução adotado.

The effects of fisheries management on the Icelandic demersal fish value chain

Iceland׳s fishing industry has outperformed fishing industries in neighboring countries in recent years. This paper identifies key factors in market structure in recent decades that contribute to long run profitability of the Icelandic fishing (and fish processing) industry using semi-structured interviews with industry participants, and compares those with similar results from Norway. Further, the development of profitability in the Icelandic and Norwegian demersal fishing industries is used to assess the long run effects of different management systems on quality, product focus and profitability. The results indicate that three key changes in Icelandic regulation during the 1980s were important to the development of long run profitability within the fishing industry: the abolition of export barriers, the introduction of an individual transferable quota (ITQ) system and the establishment of fish auctions. A large and growing literature supports the role of ITQs in ensuring long run profitability. The importance of market structure for profitability has only recently been identified, affecting the ability of value chains to become market oriented and supply homogenous product flow from heterogeneous raw material. Comparison with Norway indicates that while individual transferable quota management does improve profitability in fishing to a certain extent, management systems must facilitate a strong market connection from consumers, through the stages of retail and processing, to fishers for the full realization of profit potential in the fishing industry.

Effects of different management systems on root distribution of maize

Wang, Z., Ma, B.-L., Gao, J. and Sun, J. 2015. Effects of different management systems on root distribution of maize. Can. J. Plant Sci. 95: 21–28. Characterization of root distribution in maize (Zea mays L.) is important for optimizing agronomic management to match crop requirements, while maximizing grain yield, especially under intensive management. The objectives of this study were to examine the differences in maize root distribution between two management systems and to identify root-related factors that could be adjusted for further yield improvement. A 4-yr field experiment examined maize root distribution under two management systems: farmers’ practices (FP: low plant density, unbalanced fertilization) and high yield strategies (HY: high plant density, sufficient fertilization). Root mass distribution within the soil profile was more restricted horizontally within 10 cm from the stalk base and vertically below 20 cm in HY compared with FP. HY had a greater proportion of fine roots (diameter ≤ 0.5 mm) and more roots per 100 kernels than FP. However, per-plant root weight was not significantly affected by type of management system. Yield was positively correlated with total root number and the ratio of root mass below 20 cm to total root mass. Our data indicate that HY maize overcame the negative effect of crowding stress by producing more roots with smaller root diameters, and maize root systems became narrower and were distributed deeper under intensive management compared with traditional famers’ practices.

Aggregate stability by the "high energy moisture characteristic" method in an oxisol under differentiated management

Studies testing the High Energy Moisture Characteristic (HEMC) technique in tropical soils are still incipient. By this method, the effects of different management systems can be evaluated. This study investigated the aggregation state of an Oxisol under coffee with Brachiaria between crop rows and surface-applied gypsum rates using HEMC. Soil in an experimental area in the Upper São Francisco region, Minas Gerais, was studied at depths of 0.05 and 0.20 m in coffee rows. The treatments consisted of 0, 7, and 28 Mg ha-1 of agricultural gypsum rates distributed on the soil surface of the coffee rows, between which Brachiaria was grown and periodically cut, and compared with a treatment without Brachiaria between coffee rows and no gypsum application. To determine the aggregation state using the HEMC method, soil aggregates were placed in a Büchner funnel (500 mL) and wetted using a peristaltic pump with a volumetric syringe. The wetting was applied increasingly at two pre-set speeds: slow (2 mm h-1) and fast (100 mm h-1). Once saturated, the aggregates were exposed to a gradually increasing tension by the displacement of a water column (varying from 0 to 30 cm) to obtain the moisture retention curve [M = f (Ψ) ], underlying the calculation of the stability parameters: modal suction, volume of drainable pores (VDP), stability index (slow and fast), VDP ratio, and stability ratio. The HEMC method conferred sensitivity in quantifying the aggregate stability parameters, and independent of whether gypsum was used, the soil managed with Brachiaria between the coffee rows, with regular cuts discharged in the crop row direction, exhibited a decreased susceptibility to disaggregation.

Soil and crop management and biomass removal effects on soil organic matter content in Hungary

Greater use of biomass for bioenergy has increased the need to evaluate above ground biomass removal (BR) effects on soil quality components, especially soil organic matter (SOM). A multifactor, 40 year fi eld experiment was conducted in Kompolt, Hungary on a carbonate-free, slightly acidic chernozem brown forest soil (USDA: Ustolls) with the objective of determining the effect of different management systems with concurrent removal of the above ground biomass on the SOM content of the 0-320 mm layer. A multifactor experiment composed of treatments involving different crop rotation (CR), beef manure application, mineral fertiliser application, above ground BR (vs. biomass incorporation, BI) and lucerne management options for different rotations are the basis of this study. CR had no signifi cant effect on SOM content. Management options that included a four year lucerne stand produced signifi cantly higher SOM content in fi ve out of six fertiliser and biomass management combinations. Continuous manure applications and manure + NPK fertiliser resulted in a signifi cantly greater SOM content than management options that minimised or eliminated fertiliser or manure additions. SOM content for different soil amendments and biomass treatments ranked: BR < NPK + BR < BI < manure + BR = NPK + manure + BR with SOM contents of 2.75 < 2.82 < 2.87 < 2.92 per cent (w/w) respectively. Manure had the most profound effect because its signifi cance was most consistent across a range of management combinations and years. The results suggest that agricultural management systems that include lucerne and manure application have the potential to sustain SOM content with concurrent above ground BR in continental climates on Ustolls with near level topography.

Soil and crop management and biomass removal effects on soil organic matter content in Hungary

Greater use of biomass for bioenergy has increased the need to evaluate above ground biomass removal (BR) effects on soil quality components, especially soil organic matter (SOM). A multifactor, 40 year fi eld experiment was conducted in Kompolt, Hungary on a carbonate-free, slightly acidic chernozem brown forest soil (USDA: Ustolls) with the objective of determining the effect of different management systems with concurrent removal of the above ground biomass on the SOM content of the 0-320 mm layer. A multifactor experiment composed of treatments involving different crop rotation (CR), beef manure application, mineral fertiliser application, above ground BR (vs. biomass incorporation, BI) and lucerne management options for different rotations are the basis of this study. CR had no signifi cant effect on SOM content. Management options that included a four year lucerne stand produced signifi cantly higher SOM content in fi ve out of six fertiliser and biomass management combinations. Continuous manure applications and manure + NPK fertiliser resulted in a signifi cantly greater SOM content than management options that minimised or eliminated fertiliser or manure additions. SOM content for different soil amendments and biomass treatments ranked: BR < NPK + BR < BI < manure + BR = NPK + manure + BR with SOM contents of 2.75 < 2.82 < 2.87 < 2.92 per cent (w/w) respectively. Manure had the most profound effect because its signifi cance was most consistent across a range of management combinations and years. The results suggest that agricultural management systems that include lucerne and manure application have the potential to sustain SOM content with concurrent above ground BR in continental climates on Ustolls with near level topography.

Effect of different management systems on growth, endocrine parameters and puberty in Hereford female calves grazing Campos grassland

This study compared different management systems applied early in life on body development, endocrine parameters and age at puberty in beef heifers grazing Campos grassland, from 75 to 539±1.5 days of age. Calves were allocated to three treatments: (1) Early weaning (EW, n=15) at 75±1.5 days of age; (2) Traditional weaning (TW, n=14) at 158±1.5 days of age; (3) Traditional weaning plus creep feeding (TW+CF, n=17). Early weaned and TW+CF calves received a supplement that supplied 26±1.1% of crude protein and 11.7±0.04MJ ME/kg DM from 75 to 158±1.5 days. Traditional weaned calves had a greater average daily weight gain (0.86±0.03kg/day; ADWG) than EW calves (0.75±0.03kg/day) from 75 to 158±1.5 days, associated with greater IGF-I concentrations at the time of TW (112.9±10.7 and 63.4±10.3ng/mL respectively; P<0.05) that had no impact on age at puberty. Traditional weaning plus CF calves had a superior ADWG from 75 to 158±1.5 days (1.25±0.03kg/day; P<0.05), greater concentrations of IGF-I at weaning (185.3±9.6ng/mL), were heavier and taller (P<0.02) from weaning to 539±1.5 days, and puberty occurred earlier (472±8.0 days of age) than EW (526±7.2 days of age; P<0.05) and tended to occur earlier than TW calves (484±3.4 days of age; P=0.06). We conclude that age at weaning had a short-term impact on body growth and IGF-I concentrations, that had no effects on the age at puberty. However, CF induced a faster body development, which was related to an earlier attainment of puberty.

Efeito de sistemas de manejo do solo e velocidade de semeadura no desenvolvimento do sorgo forrageiro

O sorgo forrageiro é uma gramínea indicada para cultivo em ambientes secos e quentes, nos quais a produtividade de outras forrageiras pode ser antieconômica. Objetivou-se, com este trabalho, estudar diferentes sistemas de manejo e diferentes velocidades de semeadura, no desenvolvimento do sorgo forrageiro cv. BRS 610. O solo da área experimental foi um Nitossolo Vermelho distroférrico. O experimento foi instalado em condições de campo, na FCA/UNESP, Campus de Botucatu-SP, utilizando-se o delineamento em blocos ao acaso, em esquema de parcela subdividida, com dezesseis tratamentos (quatro sistemas de manejo e quatro velocidades de semeadura). Os sistemas de manejo utilizados foram: semeadura direta; gradagem pesada; gradagem pesada + duas gradagens leves e escarificação. As velocidades na operação de semeadura utilizadas foram: 3, 5, 6 e 9 km h-1. Foram analisadas as seguintes variáveis: população de plantas, altura de plantas, diâmetro do colmo, massa de mil grãos e produtividades de massa verde e de massa seca. O sistema de semeadura direta foi o que proporcionou maior população de plantas, maior diâmetro do colmo e maior produção de massas verde e seca. Com o aumento da velocidade na operação de semeadura, houve redução da população de plantas e aumento do diâmetro do colmo. A velocidade de 5 km h-1 foi a que proporcionou maior produção de massas verde e seca (kg ha-1), seguida da velocidade de 3 km h-1.

Effect of different management systems on rutting behavior and behavioral repertoire of housed Maghrebi male camels (Camelus dromedarius)

Camel management has been changing in recent years from an extensive to a semi-intensive or intensive system, particularly for breeding bulls and dairy dromedary camels. Captivity may affect animal welfare, and low libido is the major complaint for housed breeding bulls. Since welfare status could also affect reproductive performance, the aim of this study was to evaluate different management practices on behavior, particularly on sexual behavior, and to identify some behavioral needs of male dromedary camels reared for semen collection. The effects of the following management systems on their behavior were compared: (i) traditional: housing in a single stall for 24 h (H24), (ii) housing in a single stall for 23 h with 1 h free in the paddock (H23), and (iii) housing in a single stall for 22 h and 30 min with 1 h paddock time and 30 min exposure to a female camel herd (ExF). During the trial, blood cortisol concentrations were assessed and camels were filmed daily for 30 min in the mornings and during a female passage in the evenings. Videos were analyzed in order to fill out a focal sampling ethogram and to score sexual behavior. As a result, there were no differences between the H24 and H23 systems, whereas ExF had a significant positive impact on their sexual behavior score and behavioral repertoire, further reducing cortisol levels. Overall, it seems that male dromedary camel welfare status improves when their behavioral needs for social interaction and movement are satisfied.

Effects of three whole-farmlet management systems on Merino ewe fat scores and reproduction

As part of the Cicerone Project’s whole-farmlet experiment on the Northern Tablelands of New South Wales, Australia, the fat scores and reproductive performance of ewes were measured to assess the effect of different management systems on these important production parameters over time. The three farmlets (each of 53 ha) included one (farmlet B) subjected to ‘typical’ district management consisting of moderate levels of inputs and a target stocking rate of 7.5 dse/ha, with flexible grazing management across eight paddocks. A second farmlet (A) was managed in a similar fashion to farmlet B with respect to number of paddocks and grazing management, but modified by high rates of pasture renovation and higher levels of soil fertility, with a target stocking rate of 15 dse/ha. The third farmlet (C) was managed at the same level of moderate inputs as farmlet B but employed intensive rotational grazing over 37 paddocks and also had a high target stocking rate of 15 dse/ha. The experiment was conducted over 6.5 years from July 2000 to December 2006. In spite of the fact that target levels of stocking rate were chosen at the beginning of the experiment, stocking rate, together with fat scores and reproduction were treated as emergent properties of each farmlet system. Joining took place in April–May and lambing occurred in September–October of each year. Over the first 2 years of the experiment, there were few differences among farmlets in ewe fat scores or reproductive performance. From 2003 onwards, while the percentage of ewes pregnant was similar between farmlets, the average proportion of multiple births (ewes scanned in late July, with twins) was 30%, 16% and 12%, respectively, on farmlets A–C. However, lamb losses were greater on farmlet A, with average lamb mortalities recorded on farmlets A–C of 29%, 10% and 19%, respectively. Over the duration of the experiment, ewes on farmlets A and B were more often above a fat score level of 3, and less often below 2.5, than were ewes from farmlet C. Differences among farmlet ewes in fat score were found to be significant in 7 of the total of 13 assessments over the duration of the experiment. A generalised additive model applied to whole-farmlet data showed that green digestible herbage, legume herbage, stocking rate, the amount of supplement fed and especially the proportion of each farmlet grazed at any one time all influenced fat scores of ewes. While fat scores and conception rates tended to be highest on farmlet A, farmlet B had slightly better reproductive outcomes due to less lambing losses, whereas ewes on farmlet C tended to have somewhat lower fat scores and levels of reproduction. These farmlet-scale findings highlighted the importance for livestock managers to focus not only on grazing management, stocking rate and stock density during lambing, but also on the availability of sufficient green, and especially legume herbage, and the difficulty of overcoming a deficit in quality herbage with supplementation.

Influência de adubações e manejo de adubo verde nos atributos biológicos de solo cultivado com alface (Lactuca sativa L.) em sistema de cultivo orgânico

Devido à carência de informações sobre adubação orgânica para alface e uma avaliação quanto à sua influência nos atributos biológicos do ambiente, este trabalho objetivou estudar o efeito de diferentes sistemas de manejo da mucuna preta e o uso de adubação orgânica sólida sobre a diversidade e biomassa microbiana do solo. Os tratamentos consistiram do manejo da mucuna preta, incorporada ou não ao solo, e aplicação de esterco bovino, composto, adubo orgânico comercial e testemunha sem adubação. Os atributos foram avaliados nas seguintes épocas: momento do manejo da mucuna e aos 15, 55 e 105 dias após esse manejo. O manejo e os tratamentos com adubo orgânico sólido não influenciaram de forma significativa na biomassa microbiana e na população bacteriana do solo. Houve aumento na população de fungo coma incorporação da mucuna preta. A incorporação da mucuna preta e o tratamento com composto foram favoráveis para o incremento de fungos micorrízicos. O tratamento com composto, seguido da incorporação da mucuna preta, e o tratamento testemunha proporcionaram população superior de nematoides saprófitas, enquanto a incorporação da mucuna ao solo aumentou as populações de fitonematoides.