Hay Crop Research Articles

Lucratividade e risco de sistemas de produção de grãos com pastagens, sob sistema plantio direto

O objetivo deste estudo de cinco anos foi avaliar o desempenho de cinco sistemas de produção: sistema I (trigo/soja, ervilhaca/milho e aveia branca/soja); sistema II (trigo/soja, pastagem de aveia preta + ervilhaca/milho e aveia branca/soja); sistema III [pastagem perene de estação fria (festuca + trevo branco + trevo vermelho + cornichão)]; sistema IV [pastagem perene de estação quente (pensacola + aveia preta + azevém + trevo branco + trevo vermelho + cornichão)]; e sistema V (alfafa para feno). As parcelas dos sistemas III, IV e V, retornaram para o sistema I, a partir do verão de 1996. O delineamento experimental foi em blocos ao acaso, com quatro repetições. Foram aplicados à receita líquida quatro tipos de análise nos sistemas de produção: análise da receita líquida, da média variância, da distribuição de probabilidade acumulada e da dominância estocástica. Pela análise da receita líquida e da média variância, não houve diferença significativa entre os sistemas estudados. O sistema IV mostrou-se a melhor alternativa de produção, levando-se em conta lucratividade e menor risco, pela análise da dominância estocástica.

Effect of crop rotations on NO3 leached over 17 years in a medium-textured Brown Chernozem

High NO3 concentration in drinking water can be a health hazard, but properly fertilized rotations containing cereals and pulses or perennial grasses reduce the risk of NO3 leaching. Over fertilization, and sometimes under fertilization, frequent summer fallowing, and use of legume green manure may increase the risk of NO3 leaching in subhumid areas. We used a crop rotation study, initiated in 1987 on a medium-textured Brown Chernozem at Swift Current, Saskatchewan, to determine the influence of cropping frequency, legume green manure, wheat class and grass hay crop on NO3-N leached beyond the rooting depth of cereals (1.2 m) after 17 yr. Nitrate distribution in the soil to 2.4 m was measured in 1987 and again in 2003. All rotations received N and P fertilizer based on soil tests, and were generally managed using no-tillage. The period had 4% more precipitation than the long-term average (367 mm) with 5 yr exceeding the average by >13%. A comparison of NO3-N content below 1.2 m depth in 1987 and 2003 showed no significant (P < 0.05) leaching has occurred, although the legume (Lens culinaris L.) green manure-wheat-wheat (Triticum aestivum L.) system showed evidence it may eventually leach NO3. Contrary to expectations, continuous-wheat, because of higher N applied and possibly because net N mineralization is small under no-tillage, tended to leach more NO3 than fallow-containing rotations (P = 0.09). Crested Wheatgrass (Agropyron cristatum L. Gaertn) reduced NO3 content to 2.4 m because it is a perennial with deep and extensive roots. There was no effect of wheat class on the amount of NO3 leached. Key words: Cropping frequency, wheat class, lentil green manure, crested wheatgrass

Closing the nutrient loop between urban and rural area – wastewater and sludge utilization in Ner River Valley

For decades an area of 4 500ha of Ner River valley was used as a part of Łódź municipality wastewater treatment system. Sandy alluvial soils were irrigated with nutrient rich river water for high hay crop production.Nowadays wastewater treatment plant in Łódź discharges 2m3s−1 of wastewater and produces daily 30–35t of dry matter of sludge which can be utilized in the valley for energy biomass production.Of a great importance for sustainable development is the recirculation of nutrients between urban and rural areas. Reuse nutrient rich wastewater and sludge results in saving natural resources (mining rocks, forest wood) and protection of receiving water bodies.

Bag Silo Densities and Losses

Bag silos made at three research farms in 2000 and 2001 were monitored at filling and emptying to determine densities and losses. A total of 47 bags (23 alfalfa, 1 red clover, 23 whole-plant corn) were made, and losses were calculated on 39 of the silos. Dry matter (DM) density ranged from 160 to 270 kg/m3. Dry matter density increased with DM content in hay crop silages on average 2.9 kg/m3-% DM, whereas the effect in corn silage varied by bagging machine. Density decreased with increasing particle size at 4.1 kg DM/m3 per mm. The operator and the bagging machine setup both affected density. A wide range (0% to 40%) of DM losses was observed. Average DM losses were 9.2% invisible plus uncollected losses and 5.4% spoilage losses, for a total loss of 14.6%. Six silos had excessive spoilage losses of more than 15% and total losses above 25% due to plastic integrity issues or overly dry silage (>40% DM) being fed out in warm weather. Invisible losses were reduced in high-porosity silages (where spoilage losses were exacerbated), greater in warm weather, and affected by emptying procedures. Spoilage losses in bags without plastic integrity issues were greater in dry silages, from emptying silos in warm weather, at lower feed-out rates, in bags stored for a long time, and if bags were emptied periodically rather than daily.

Tree establishment and growth using forage ground covers in an alley-cropped system in Midwestern USA

The integration of forage crops in an alley-cropped system was examined as a method of encouraging tree planting to increase farm income, improve soil quality, and enhance biodiversity on Midwestern U.S. farms. Crop and tree performance were evaluated in an alley-cropped system using four forage intercrops grown in tree alleyways to simulate a potential hay crop – oat (Avena sativa L.) and red clover (Trifolium pratense L.); oat, red clover, and red fescue (Festuca rubra L.); oat, red clover, and orchardgrass (Dactylis glomerata L.); and oat and hairy vetch (Vicia villosa Roth) – compared to a herbicide, mowing and control (no management) treatment. Five tree species, divided into fast-growing hardwoods of two poplar (Populus spp.) clones [Crandon (P. alba L. × P. grandidentata Michx.) and Eugenei (P. deltoids Bartr. × P. nigra L.)], and silver maple (Acer saccharinum L.) were compared with two high-value, slow-growing hardwoods planted from seed and as seedlings: red oak (Quercus rubra L.) and black walnut (Juglans nigra L.). Tree survival in the first year was greater for the fast-growing species, and by the fourth year, tree height among the four forage treatments was equivalent for all upland locations. The oat/hairy vetch ground cover was associated with the shortest trees in the bottomland site. Herbicide-treated trees were taller than the average of the four forage treatments for all four planting conditions. Tree height in the mowing and the control treatments was not significantly different for all four planting conditions. The nutritive value of the forage crop was excellent in the second year of tree establishment, with crude protein content and digestibility at 17 and 71%, respectively, in the oat/red clover/red fescue treatment, suggesting the viability of forage crops as alternatives to herbicides in alley-cropped systems.

Agronomic performance of Pesticide Free Production under two crop rotations

AbstractPesticide Free Production (PFP) is a pesticide reduction system that removes in-crop pesticide use on a yearly basis. A long-term study was established in 2000 to investigate the effect of crop rotation and frequency of inclusion on the success of PFP, as well as the effect of PFP on subsequent crops in the rotation. The crop rotations being compared were linola–oat–canola–wheat and linola–oat–alfalfa–alfalfa. PFP occurred either once in the rotation (oat) or twice (linola–oat). Weed density and yield were measured in the crops that followed PFP. Oat was a more successful PFP crop than linola because it was better able to compete with weeds. Furthermore, PFP oat had a higher weed density when it followed PFP linola, but this did not influence PFP oat yield. Under the conditions of this study, PFP linola was more successful in the annual crop rotation. Inclusion of alfalfa hay crops in the crop rotation was not effective in lowering weed pressure and, in fact, may have contributed to an increase in weed density. It is concluded that weed species present influenced the effectiveness of alfalfa in facilitating PFP, because major weeds in the study are not effectively controlled by alfalfa. PFP did not have a negative effect on following crops in the rotation (i.e. canola–wheat or alfalfa), regardless of whether one or two consecutive years of PFP occurred in the rotation. No additional herbicide was necessary for weed control in the crops that followed PFP; however, alfalfa hay was weedier for the first year following PFP. This study indicates that PFP is a viable way to reduce herbicide use in a cropping system and that attention needs to be paid to PFP crop selection and crop rotation, particularly when the PFP crop is less competitive with weeds.

Evaluation of Dry Matter Loss, Nutritive Value, and In Situ Dry Matter Disappearance for Wilting Orchardgrass and Bermudagrass Forages Damaged by Simulated Rainfall

Throughout much of the southeastern USA, hay harvest can be complicated by a high probability of rainfall events that may cause damage to the resultant hay crop. The objectives of this study were to investigate the effects of simulated rainfall and two postrainfall drying methods on losses of dry matter (DM) and changes in nutritive value for wilting orchardgrass (Dactylis glomerata L.) and bermudagrass [Cynodon dactylon (L.) Pers.] forages. Orchardgrass was wilted to moisture concentrations of 674 (WET), 153 (IDEAL), and 41 (DRY) g kg−1 and subjected to 0, 12, 25, 38, 51, 64, or 76 mm of simulated rainfall from a custom‐built rainfall simulator. For IDEAL orchardgrass, DM loss reached a maximum of 88 g kg−1 when 76 mm of simulated rainfall was applied. Dry matter loss, total N, and all fiber components except hemicellulose increased with rainfall amount, exhibiting single or multiple polynomial effects (P ≤ 0.048) in each case; however, responses were not consistent across these response variables. A second study was conducted with bermudagrass using similar techniques, except that the forage contained 761 (WET), 400 (MID), and 130 (IDEAL) g kg−1 of moisture when simulated rainfall was applied. For IDEAL bermudagrass forage, DM losses increased in linear (P = 0.001) and quadratic (P = 0.003) relationships with simulated rainfall, but the maximum DM loss was only 21 g kg−1. For both forages, DM loss and deleterious changes in nutritive value generally increased with rainfall amount, but these responses appeared to be much greater for orchardgrass.

Producer Attitudes Regarding Timothy Hay Production in Northern Idaho and the Surrounding Region

ABSTRACT Perennial hay crops on a large scale and as a major source of income are new to northern Idaho farmers. These crops can make an important contribution to erosion control and sustainability in this region that has soil erosion rates amongst the highest in the country. This study evaluated the current situation and future perceptions about hay production and marketing using a farm survey. Results indicated that growers in northern Idaho were optimistic about hay production, particularly timothy, by committing to a possible future increase in production. The current level of hay production, presence of a hay compressor nearby, priority of hay production, and contract availability are important factors influencing future hay production. More commitment needs to be made by producers who are willing to grow good-quality hay. Growers need to consider production timelines, targeting markets, and quality specifications before making such a commitment.

Potassium Management for Brown Midrib Sorghum × Sudangrass as Replacement for Corn Silage in the North‐eastern USA

AbstractIn recent years, there has been a growing interest in brown midrib (BMR) sorghum (Sorghum bicolor (L.) Moench.) × sudangrass (Sorghum sudanense Piper) hybrids (SxS) as a replacement for silage corn (Zea mays L.) in the north‐eastern USA. Recent studies suggest it is suitable for both rotational grazing and as a hay crop and could compete with corn harvested for silage in years when wet spring conditions prevent the timely planting of corn. However, little is known about its suitability as forage for non‐lactating cows that require low potassium (K) forages to prevent health problems. Our objective was to evaluate the impact of K fertilizer management (0, 112 or 224 kg K2O ha−1 cut−1) under optimum N management (112–168 kg N ha−1 cut−1) on yield, quality and K concentrations of BMR SxS over a 2‐year period. Field trials were established on a fine loamy, mixed, active, mesic Aeric Fragiaquepts with medium K‐supplying capacity and characteristic of a large region in New York. Potassium application did not affect dry matter yields in either of the 2 years. Averaged over 2 years, neutral detergent fibre (NDF) significantly increased with K addition with similar but non‐significant trends observed in each of the years individually. The digestibility of NDF was unaffected by K application. Crude protein (CP) concentrations showed a significant decrease with K application in 2002 and similar trends were observed in 2003, although differences were not significant at P ≤ 0.05. The changes in NDF and CP did not significantly impact forage quality expressed as milk production per megagram of silage. Potassium application increased forage K concentration up to 13 mg K kg−1 dry matter (in the first cut in 2003). Forage Ca and Mg concentrations decreased with K addition except for the first cut in 2002 where differences between 112 and 224 kg K2O ha−1 treatments were not significant. Without K addition in the 2‐year period, K concentrations in the forage decreased from 23 g kg−1 for the first cutting in 2002 to 15 g kg−1 for the second cut in 2003. Low K forage was obtained for all second‐cut forage unless 224 kg K2O ha−1 cut−1 had been added. First‐cut forage was suitable only when no additional K had been applied. These results suggest low K BMR SxS forage can be harvested from initially high K soils without loss in dry matter yield as long as no additional K is added.

EFFECTIVENESS OF A PASSIVE FEEDLOT RUNOFF CONTROL SYSTEM USING A VEGETATIVE TREATMENT AREA FOR NITROGEN CONTROL

This study was initiated to investigate the effectiveness of a solids basin and vegetative treatment area (VTA) fornutrient control as a low-cost alternative to runoff holding ponds for cattle feedlots. The estimated total nitrogen load enteringthe VTA was equivalent to/or less than the total nitrogen load removed by the hay crop harvested from the VTA. No water wasmeasured exiting the VTA, either by deep percolation or by direct release, during the four-year study period. As a result, thedischarge water from the basin was effectively used for hay crop production. Electromagnetic induction maps were producedto illustrate zones within the VTA where salt and nutrient loading occurred. Soil analyses in these zones indicated that surfacesoil NO3-N levels, particularly closest to the discharge tubes, had increased. Currently nitrogen is contained near the surface,and has not started to infiltrate deeper into the VTA soil. However, NO3-N appears to be infiltrating below the solids basinwhere concentrations as high as 60 mg NO3-N kg-1 soil were measured to a depth of 3 m. Annual removal of the solids andorganic material from the solids basin may have compromised sealing of the basin. Seepage monitoring will continue in thenear term.

Observations on Changes in Kazak Pastoral Use in Two Townships in Western China: A Loss of Traditions

Abstract We provide observations regarding changes in pastoral use within two Kazak areas in the People's Republic of China to illustrate how very different pastoral use can be in similar areas within the same cultural group. The first area is Jianshe Township of Aksai Kazak Autonomous County, in western Gansu Province. The second area is Kurti Township in Fuyun County, Xinjiang Uighur Autonomous Region. In both townships, livestock production from extensive rangelands was the primary economic activity. Our main reason for examining rangeland issues arose from a general view among county officials that overgrazing was threatening rangeland sustainability. Kazak pastoralists were traditional users in the study areas, at least for most of the twentieth century. By the time of our study, the largely Kazak-owned herds in Jianshe had given way to a Han majority, and traditional pastoral practices had been largely replaced by inexperienced contract herders who originated from other regions of China. The change to contract herders with little livestock experience may be a serious threat to sustainable grazing management as traditional ecological knowledge has been lost. In Kurti Township, Kazaks have maintained more traditional movement of livestock, with some herders moving 400 km between winter and summer pastures. However, even in this area the traditional Kazak pastoral culture is threatened from both within (Kazaks themselves) and from outside (policies from Beijing) by attempts to settle herders. In this township, agriculture has become important along rivers, herders are securing rights over irrigated lands to produce hay crops, and many complain of the long distances between pastures and want to become settled.

Companion crop establishment of short-lived perennial forage crops in Saskatchewan

Short-lived perennial forages may provide producers with a cash hay crop as a viable option to diversify annual grain rotations. Little or no information on alternative annual crops for companion crop establishment of forages is available for Saskatchewan conditions. We evaluated field pea (Pisum sativum), canola (Brassica napus), and Westerwolds ryegrass (Lolium westerwoldicum) as companion crops over 3 yr (1998–2000) at three Saskatchewan sites: Swift Current (Brown soil zone), Saskatoon (Dark Brown) and Nipawin (Dark Gray). We also compared three short-lived, vigourous grass species in mixture with two alfalfa (Medicago sativa) cultivars or monoculture. Combinations of precipitation and temperature variables combined with companion crop plant density and biomass explained 90% of the variation in forage yield loss relative to no companion crop forage yield. We conclude that companion crops can be used with low yield reductions at Nipawin, but that all three companion crops significantly reduced forage yield at Swift Current. Forage seedling density was reduced under companion crops but the decline in forage seedling density did not explain the reduction in forage yield. We speculate that yield components rather than plant density must have been affected by companion crop competition. Intermediate wheatgrass (Elytrigia intermedia) produced higher forage yield than Dahurian wildrye (Elymus dahuricus) or slender wheatgrass (Elymus trachycaulus). Grass-alfalfa mixtures produced higher forage yield than grass mono culture. Economic returns were superior if no companion crop was used to establish the forages at Swift Current and Saskatoon; but, at Nipawin economic returns were generally higher with companion crop establishment. The feasibility of companion crops for establishment of short-lived perennial forages in Saskatchewan thus depends on soil zone, with their use best suited to the more humid regions. Key words: Forage yield, plant density, weather, economics

Towards improving white clover establishment on farms

The establishment of new clover-based pastures takes a full year and has two distinct components; seedling emergence from sowing, and subsequent grazing management. A Ministry of Agriculture and Forestry (MAF) Sustainable Farming Fund (SFF) project to investigate the causes of inconsistency of white clover establishment concluded this came primarily from a lack of knowledge of white clover in both sowing and grazing management skills, and reflected how far modern farming technology has moved away from clover-based systems towards nitrogen (N)-boosted systems in recent years. Typically, less than half the seed being sown emerges, for both ryegrass and clover, although good results do occur. A trial looking into seedbed conditions on a dairy farm highlighted the importance of good seedbed consolidation in order to accurately control sowing depth, lifting white clover emergence by 50% and ryegrass by 25% using a roller drill. Consolidation did not affect emergence using a triple disc drill, but it did improve quality of sowing by reducing soil drag and spill by the rear coulters causing excessive burial of the front coulters rows. Differences in emergence were still evident in the performance of the clover in the following summer with 14% clover in the areas that had been hard rolled compared to 4% where it had not. In another trial on a hill soil of lower N fertility status, the taking of hay crops in the first summer, not a normally recommended practise, enhanced clover establishment compared to rotational grazing all year. The roles of clover, N fixation and quality feed, are discussed in the context of how and where clover may fit into modern farm systems. Keywords: emergence, establishment, grazing management, seedbed preparation, sowing methods, white clover

Evaluating the performance of alfalfa cultivars in rotationally grazed pastures

Although alfalfa (Medicago sativa L.) is an important and reliable hay crop in eastern Canada, it is generally not considered suitable for pastures. However, local studies have shown that alfalfa is capable of superior yield in mixtures under rotational grazing. This study evaluates the performance of commercially available, locally adapted, hay-type alfalfa cultivars and new experimental, grazing-type alfalfa synthetics under hay and two rotationally grazed regimes. Ten alfalfa cultivars, including five hay-type and five grazing-type cultivars, were seeded with the timothy (Phleum pratense L.) cultivar, Richmond, in mixtures. The two pasture regimes consisted of grazing to low and high residual heights. Over two dry growing seasons, the pasture management with high residual grazing height was more productive than the low; on average lenient rotational grazing pressure (high residual heights) produced 20% higher yield than low residual heights. Alfalfa cultivars selected specifically for continuous grazing were not, on average, superior to those hay-type cultivars selected for general adaptability to soil and environmental conditions in Atlantic Canada. Differences among cultivars within alfalfa type were significant. Over 2 production years, mixtures containing the hay-type cultivar, Apica, and the grazing type, Alfagraze, produced more dry matter on average than three others in the study, regardless of management regime. Key words: Grazing height, cattle grazing

Comparison of Bermudagrass, Bahiagrass, and Kikuyugrass as a Standing Hay Crop

Stockpiling of warm‐season perennial grasses for grazing after frost is a management practice that can lower livestock production costs. Six seeded bermudagrass [Cynodon dactylon (L.) Pers.] cultivars, two bahiagrass (Paspalum notatum Flugge) cultivars, and a kikuyugrass (Pennisetum clandestinum Hochst. ex Chiov.) cultivar were compared with ‘Coastal’ and ‘Tifton 85’ bermudagrass in a small plot study in northeast Texas. Plots were sampled monthly from October through February in 1999 through 2002 to monitor accumulated dry matter (DM), crude protein (CP), and acid detergent fiber (ADF). Initial standing forage mass was <3000 kg DM ha−1 and remained relatively stable during the sampling period in the first 2 yr. In the third year, initial standing forage mass was >4000 kg DM ha−1 and declined during the sampling period for all entries. Standing forage mass of Tifton 85 bermudagrass was usually greater than the other entries. Crude protein decreased with time, but the rate of decline was related to initial CP concentrations and forage maturity at first frost. Bahiagrass cultivars and kikuyugrass generally had higher CP concentrations than bermudagrass cultivars. Crude protein concentrations were always above the minimum requirements for mature, nonlactating, pregnant beef cows (70–80 g kg−1). Acid detergent fiber increased with time for all entries, with the largest monthly increase usually occurring after December. The ADF concentration in bahiagrass cultivars was always higher than in bermudagrass cultivars and kikuyugrass. Species suitability for stockpiling forage was bermudagrass > kikuyugrass > bahiagrass. Tifton 85 was superior to the other bermudagrasses because of greatest autumn growth.

Efeitos de sistemas de produção de grãos envolvendo pastagens sob plantio direto nos atributos físicos de solo e na produtividade

A integração da lavoura com a pecuária altera a estrutura do solo, que, por sua vez, interfere nas características físicas na camada superficial. O objetivo deste trabalho foi avaliar os atributos físicos de solo e o rendimento de grãos num Latossolo Vermelho distrófico típico, em Passo Fundo (RS), oito anos após o estabelecimento (1993 a 2000) de sistemas de produção com culturas produtoras de grãos e forrageiras sob pastejo: (I) trigo/soja, aveia branca/soja e ervilhaca/milho; (II) trigo/soja, aveia branca/soja e pastagem de aveia preta + ervilhaca/milho; (III) pastagens perenes da estação fria (festuca + trevo branco + trevo vermelho + cornichão); (IV) pastagens perenes da estação quente (pensacola + aveia preta + azevém + trevo branco + trevo vermelho + cornichão), e (V) alfafa para feno, tratamento adicional acrescentado em 1994, com repetições em áreas contíguas ao experimento. As áreas sob os sistemas III, IV e V retornaram ao sistema I a partir do verão de 1996. Os tratamentos foram distribuídos em blocos ao acaso com quatro repetições. Amostras de solo também foram coletadas em fragmento de floresta subtropical ao lado do experimento, como testemunha da condição original do solo. A densidade do solo mostrou-se maior na camada subsuperficial (10-15 cm) do que na camada superficial (0-5 cm), enquanto para os valores de porosidade total e de macroporosidade ocorreu o inverso. Nos sistemas I, II, III e IV, foram observados maiores valores de densidade do solo e menores de porosidade total e macroporosidade na camada superficial, enquanto, no sistema V e em floresta subtropical, foram encontrados menores valores de densidade e maiores de porosidade total e de macroporosidade. Não houve diferenças entre os atributos físicos para sistemas com e sem integração lavoura-pecuária. Não foram verificadas correlações significativas entre rendimento de culturas e atributos físicos de solo, exceto para macroporosidade do solo na cultura de soja na camada de 0-5 cm.

Assessing farmers' willingness to participate in water banking: a case study

This paper examines potential barriers to water banking as a tool to manage scarce water resources in the western United States. A water dispute is described in northwestern Nevada. The paper outlines the concept of water banking to manage the dispute and discusses the results of a survey to assess local farmers' willingness to participate. Results indicate that farmers are willing to fallow cropland and lease their water rights to a water bank conditionally. These conditions include: 1) farmers maintain local design, control and operation of a water bank, 2) changes to water law to prevent water right losses, 3) enable temporary water transfers to occur as part of the hay crop rotation and 4) understand and anticipate potential negative economic impacts to agriculture suppliers and other related local industries from water banking.

Soil inorganic nitrogen content in commercial potato fields in New Brunswick

Information on inorganic N content in commercial potato fields in Atlantic Canada is limited. Soil inorganic N measurements were collected from 228 commercial potato fields from 1999 to 2001. Soil NO3 content to 30 cm depth at planting ranged from 2 to 124 kg N ha-1, and was generally higher for preceding potato, red clover, or hay crops compared to preceding cereal or other crops. Soil NH4 content to 30 cm depth measured at planting ranged from 3 to 64 kg N ha-1, indicating that both soil NO3 and NH4 need to be measured to assess plant-available soil N content in spring. Soil NO3 content to 30-cm depth at tuber harvest ranged from 3 to 250 kg N ha-1, generally increased with increasing fertilizer N application rate, and differed among different potato cultivars. Soil NO3 content measured to 30-cm depth in spring ranged from 3 to 100% of soil NO3 at harvest in the preceding fall, indicating that highly variable losses of soil NO3 from the root zone occur between growing seasons. Key words: Nitrate, ammonium, Solanum tuberosum L.

Efeito de sistemas de produção mistos sob plantio direto sobre fertilidade do solo após oito anos

Os atributos de solo relativos à sua fertilidade foram avaliados num Latossolo Vermelho distrófico típico, em Passo Fundo (RS), oito anos após o estabelecimento (1993 a 2000) de cinco sistemas de produção que integravam culturas produtoras de grãos, pastagens de inverno e pastagens perenes - sistema I (trigo/soja, aveia branca/soja e ervilhaca/milho); sistema II (trigo/soja, aveia branca/soja e pastagem de aveia preta + ervilhaca/milho); sistema III [pastagens perenes da estação fria (festuca + trevo branco + trevo vermelho + cornichão)]; sistema IV [pastagens perenes da estação quente (pensacola + aveia preta + azevém + trevo branco + trevo vermelho + cornichão)]; e sistema V (alfafa para feno), que foi acrescentado como tratamento adicional, com repetições em áreas contíguas ao experimento, em 1994. As áreas sob os sistemas III, IV e V retornaram ao sistema I, a partir do verão de 1996. As culturas, tanto de inverno como de verão, foram estabelecidas sob plantio direto. Os tratamentos foram distribuídos em blocos ao acaso com quatro repetições. Os valores de pH, de Al trocável, de Ca + Mg trocáveis, de matéria orgânica, de P extraível e de K trocável foram influenciados pelos sistemas de produção. Os sistemas de produção elevaram os níveis de matéria orgânica, de P extraível e de K trocável, principalmente na profundidade de solo de 0-5 cm. Os teores de matéria orgânica e os de Al trocável, de P extraível e de K trocável diminuíram da camada de 0-5 cm para a camada de 15-20 cm, enquanto para os valores de pH e de Ca + Mg trocáveis ocorreu o contrário.

PERFORMANCE OF A PASSIVE FEEDLOT RUNOFF CONTROL AND TREATMENT SYSTEM

The recent signing of the NPDES permit regulations and effluent limitations guidelines for CAFO has generated much interest from smaller beef cattle feeding operations for a more cost-effective solution for managing feedlot runoff. A passive runoff control and treatment system was constructed to reduce long-term liquid storage, provide solids separation, and evenly distribute the liquid discharge for grass hay production. The overall objective of this study was to evaluate the effectiveness of this passive system for reducing contaminant discharge. The system effectively reduced the cumulative mass of total and volatile suspended solids and reduced chemical oxygen demand by 80%, 67%, and 59%, respectively. Significant reductions of these constituents in the runoff water as it passed through the system were measured for most precipitation events. No water was measured exiting the vegetative filter strip during the three-year period of this study. Therefore, the discharge water was effectively contained and used for hay crop production. Estimated total nitrogen (TN) load in the discharge water entering the vegetative filter strip was equivalent to or less than the TN removed by the crop. System robustness was demonstrated during feedlot pen renovation when significant reductions in contaminant concentrations were measured for most all precipitation events during that period.