• Authors:
    • Silva, S. A. da
    • Bastos, E. C.
    • Fadul, M. J. do A.
    • Prado, R. B.
    • Fidalgo, E. C. C.
    • Pedreira, B. da C. C. G.
    • Zainer, N. G.
    • Peluzo, J.
    • do A. Fadul, M. J.
    • da Silva, S. A.
  • Source: Boletim de Pesquisa e Desenvolvimento - Embrapa Solos
  • Issue: 136
  • Year: 2009
  • Summary: The basins of rivers Guapi-Macacu Caceribu are located east of the basin of the Bay of Guanabara, in Rio de Janeiro and their watercourses supply water to more than two million people. Their water resources are considered of good quality, but factors such as the removal of riparian vegetation, inappropriate use of land, rectification and siltation of rivers, erosion, urban sprawl, lack of treatment of sewage and the establishment of industries, including the Rio de Janeiro's Complex Petrochemical Rio de Janeiro (COMPERJ) modify the water quality and the storage capacity of these basins. The occurrence of continuous spatial and temporal changes of use and land cover in catchment areas of rivers Guapi-Macacu Caceribu and without the support of adequate funding has caused changes in the structure of the landscape of the region and may bring undesirable consequences for the environment as for the activities of man. Thus, it is necessary to gather information and meet this dynamic process of use and coverage to support the planning of actions in the short, medium and long term, to adequate land use and improving environmental quality in river basins question. Thus, this study aimed to map the spatial-temporal use and land cover in a period previous to the installation of COMPERJ, for the years 1997 and 2007 to record the current scenario and create a starting point for monitoring region's future post-deployment of this enterprise. Mappings were performed for space-time (1997-2007) of use and land coverage using images from Landsat satellite, aerial photographs, survey of secondary data and field work. In addition, this study also aimed to analyze the effect of atmospheric correction on the multitemporal images of the region, using the method of subtraction of the gray levels in the environment ENVI 4.5. The results indicated that this method was not effective in reducing the atmospheric effects of images, and have continued to have a significant influence on the spectral response of the targets. The analysis of the dynamics of land use, the results showed that in 10 years, in terms of absolute values, changes in land cover were occasional and not very responsive. However, individually, changes occurred in some classes of use, among which can be highlighted, for example: The class vegetation in the intermediate stage of regeneration has only reduction in area (12.5 ha), which turned into pasture. Distributed throughout the study region were observed areas of suppression of vegetation in initial stage of regeneration, and noticed an increase in concentration saw Soarinho. These areas began to be occupied by pasture (275 ha), exposed soil (3 ha), water (4.8 ha) and urbanized area of low density (22.7 ha). On the other hand, there was also an increase of vegetation in initial stage of regeneration observed in the vicinity of the Mountain area, north of Macacu and southern Caceribu that was once pasture and agriculture. Was also a small increase in area of mangrove class (127.48 ha) of the APA Guapimirim. The agriculture class, the observed changes relate mainly to the areas of temporary crops. The standing crops due to its sparse distribution on the ground and are made up of small plots and/or located in the shaded, could not be identified clearly in the images. There was so much increased (701.71 ha) and reduction in class agriculture. The areas that have changed their grazing area to agricultural area totaled 891.4 ha and the reverse conversion totaled 178.4 ha. The pasture was a class that suffered the greatest reduction in area (1934.01 ha). However, it should be noted that some areas suffer seasonal changes between the pasture and agriculture, thus changing the use observed in the use class grazing were probably due to soil management and the seasonal farming activities. Moreover, in 2007 it was observed that one of the areas of pasture in 1997 became exposed soil, which is related to increased mining activities in the city of Niteroi, and partly turned into lots for development. The class exposed soil showed a significant increase in area, but that does not qualify on the change of land use, because this class were inserted the areas prepared for farming or grazing reform, which eventually may present as exposed soil. Classes urbanized area and urbanized area of low density experienced expansion in the period between 1997 and 2007, there was intensification of settlements and new areas were added from the conversion of areas previously occupied by pasture and vegetation at an early stage of regeneration. There was an increase in this period of new urban lots, predominantly in the river basin Caceribu, where there is an increasing trend of urbanization due to the installation of the Petrochemical Complex of Rio de Janeiro.Together these classes showed an increase of 504.69 ha, predominantly observed along the roads. The processes of urbanization are occurring mainly in the municipalities of Itaborai and Sao Goncalo. The class water showed an increase in area of 104.11 ha. The greatest change observed with regard to dam the beverage industry Schincariol in Waterfalls Macacu built to retain water. Part of the new areas of water are in areas occupied by mining, especially near the rivers Caceribu. It also observed an increase of small lakes in rural areas have been trained in fish farming and/or leisure activities. With respect to classes of use and coverage included in protected areas, the results indicated that there was more regeneration than removal of natural vegetation between 1997 and 2007. The best-preserved natural vegetation found in areas protected by conservation areas which inhibit the clearing of the remaining areas of Atlantic and help to maintain the quality and quantity of water in river, but does not prevent that they are progressively degraded, a factor that can be accentuated with the installation of COMPERJ.
  • Authors:
    • Feltran, J. C.
    • De Castro, C. M.
    • De Almeida, D. L.
    • Valle, Teresa L.
    • Duarte Ribeiro, R. De L.
    • Pries Devide, A. C.
  • Source: Bragantia
  • Volume: 68
  • Issue: 1
  • Year: 2009
  • Summary: Organic systems were evaluated for cassava root production directed to human comsumption in natura, at Seropedica-RJ. Treatments consisted of: cassava ('IAC 576-70') in single cropping and its intercropping with corn ('Eldorado'), cowpea ('Maua') or corn plus cowpea. The organic management was standardized and the experimental area was submitted to artificial irrigation during the period of stay of maize in the system. "Green" (immature) corn ears were harvested at the "point" required for fresh marketing and the shoot placed on the ground. The cowpea was included to function as green manure being Cut at flowering with residues left on the soil Surface. Corn and cowpea were sown between cassava rows, in an alternate design, following the first weeding of the main crop (cassava). The cultivar IAC 576-70 showed suitability with respect to organic management, yielding approximatelu 31 Mg ha(-1) of marketable roots. No significant differences were detected between cassava single cropping and any of the intercropping tested systems. Thus, corn crop has considerable potential for additional income to the growers. Yield of 'Eldorado' corn averaged 18.125 ears ha(-1) correspponding to 5,1 Mg ha-1. Residues coming from cowpea cutting brought about an input close to 12 Mg ha(-1), which meant an expressive contribution in nutrient elements, especially nitrogen (about 44 kg N ha(-1)). The legume crop, in addition, completely covered cassava inter-rows demonstrating its potential for controlling erosion and weeds. The triple intercropping becomes advantageous considering that corn harvesting would justify irrigation and that inclusion of cowpea meant benefitial effects to the system and did not interfere on cassava yield.
  • Authors:
    • Prakash, V.
    • Pandey, S. C.
    • Kundu, S.
    • Bhattacharyya, R.
    • Srivastva, A. K.
    • Gupta, H. S.
  • Source: Soil Research
  • Volume: 47
  • Issue: 6
  • Year: 2009
  • Summary: We analysed results of a long-term experiments, initiated in 1973 on a sandy loam soil under rainfed condition and in 1995-96 on a silty clay loam soil under irrigated condition, to determine the influence of using different combinations of mineral fertiliser (NPK) and fertiliser+farmyard manure (FYM) at 10 Mg/ha on soil organic carbon (SOC) content and its changes in the 0-0.45 m soil depth. Fertilisation always caused a net gain in SOC stock. Such gain was positively proportional to the amount of C incorporated into the soils. Concentration of SOC in the 0-0.45 m depth increased by 44% in NPK+FYM treated plots compared with NPK (44.4 Mg C/ha) after 32 years under rainfed condition and by 14% in the NPK+FYM treated plots compared with NPK (41.76 Mg C/ha) after 9 years under irrigation. Mean (across treatments) total C added under the rainfed and irrigated systems was 2.67 and 3.03 Mg/ha.year, respectively. It was estimated that ~20 and 25% of the gross C input contributed towards the increase in SOC content under the rainfed and irrigated systems, respectively. Carbon loss from native soil organic matter (SOM) averaged ~61 and 261 kg C/ha.year under the rainfed and irrigated systems, respectively. Furthermore, mean stabilisation of added C in the plots under the rainfed condition (~16%) was higher than that (~13%) observed under the irrigated condition. Conversion of total added C to SOC was similar in the NPK and NPK+FYM treated plots under both growing conditions. In the NPK+FYM plots, ~38 and 29% of the C added through FYM was accounted for in the form of total SOC under the rainfed and irrigated conditions, respectively. The estimated quantity of biomass C required to maintain equilibrium SOM content under the rainfed and irrigated systems was 0.29 and 1.08 Mg/ha.year. The total annual C input by the soybean-wheat rotation in the unfertilised control plots under rainfed condition was 0.87 Mg/ha.year and with N fertiliser only under the irrigated condition was 1.75 Mg/ha.year. Thus, SOC augmentation under long-term soybean-wheat cropping was due to higher annual C input than the required amount to maintain equilibrium SOM content. Although FYM addition along with NPK improved total SOC stock and carbon sequestration potential, it did not encourage the stabilisation rate of added C. Hence, C stabilisation that takes into account the total C added in the system is a better indicator of assessing SOC sequestration. In summary, mineral fertilisation improved C sequestration capacity of soybean-wheat system in the Indian Himalayas and manure addition along with mineral fertilisers further improved it.
  • Authors:
    • Raper, R. L.
    • Reddy, K. C.
    • Nyakatawa, E. Z.
    • Reddy, S. S.
    • Reeves, D. W.
    • Lemunyon, J. L.
  • Source: Field Crops Research
  • Volume: 114
  • Issue: 2
  • Year: 2009
  • Summary: Long-term field experiments are needed to fully realize positive and negative impacts of conservation tillage and poultry litter application. A study was initiated on a Decatur silt loam soil at the Tennessee Valley Research and Extension Center, Belle Mina, AL, USA in 1996 to evaluate cotton (Gossypium hirsutum L.) performance with long-term poultry litter (PL) application under different tillages and to Study the build up of phosphorus (P) With application of PL. Treatments include incomplete factorial combinations of three tillage systems [conventional till (CT), mulch till (MT), and no-till (NT)], two cropping systems [cotton-fallow and cotton-winter rye (Secale cereale L.)], and two nitrogen sources and rates [100 kg N ha(-1) from ammonium nitrate (AN), and 100 and 200 kg N ha(-1) from poultry litter (PL)]. Cotton was rotated with corn (Zea mays L.) every third year. Results from 2003 to 2008 showed that all tillages gave similar cotton lint yields with AN at 100 kg N ha(-1). Application of PL at 100 kg N ha(-1) in NT plots resulted in 12 and 11% yield reductions compared to that of CT and MT, respectively. However, NT plots with higher quantity of PL (200 kg N ha(-1)) gave similar yields to CT and MT at 100 kg N ha(-1). During corn years, higher residual fertility of PL, in terms of grain yields, was observed in NT plots compared to CT and MT. Long-term PL application (100 kg N ha(-1) year(-1)) helped to maintain original soil pH in CT and MT while AN application decreased soil pH. In NT plots, PL at 100 kg N ha(-1) was not sufficient to maintain original soil pH, but 200 kg N ha(-1) maintained original pH. Although not-significant, elevated P levels were observed in all tillages compared to original P levels which indicates possibility of P build up in future with further application of PL. Application of PL at double rate (200 kg N ha(-1)) in NT plots resulted in significant build up of P. Results indicate that NT gives similar yields to CT when received AN. but needs higher rate of PL application to achieve similar yields to CT. (C) 2009 Elsevier B,V. All rights reserved.
  • Authors:
    • Sim, R.
    • Maley, S.
    • Fletcher, A.
    • Ruiter, J. M. de
    • George, M.
    • de Ruiter, J. M.
  • Source: Proceedings of the New Zealand Grassland Association
  • Volume: 71
  • Year: 2009
  • Summary: Dairy industry strategies have demanded feeding systems with high productivity and high quality. A 45 t DM/ha annual target for feed production was addressed. Six crop sequence treatments were established in large plots (40*12 m) at Lincoln, Canterbury, in the first year of a 2-year experiment to determine practical upper limits for yield. Summer crops included maize, kale and whole crop barley and these were followed by combinations of winter crops (oats, Italian ryegrass, forage rape, tick beans and triticale). Crops were grown with minimal transition time to reduce potential yield losses, and with optimum nitrogen and irrigation management. Highest plot yield in the first annual crop cycle was 11.9 t DM/ha short of the 45 t DM/ha target. Best productivity was with a maize - triticale+tick bean (32.5 t DM/ha) sequence followed by maize - wheat (30.0 t DM/ha), barley - oats+Italian ryegrass (28.1 t DM/ha) and kale - triticale+tick bean (26.1 t DM/ha). Fertiliser management, crop water use in high input cropping systems are discussed together with practical issues around handling crops with large accumulated biomass.
  • Authors:
    • Salado-Navarro, L. R.
    • Sinclair, T. R.
  • Source: Agricultural Systems
  • Volume: 102
  • Issue: 1/3
  • Year: 2009
  • Summary: Cropping schemes have developed in east-central Argentina for rainfed soybean (Glycine max Merr.) production that invariably employ no-tillage management. Often these schemes include growing soybean in a sequence of crops including wheat ( Triticum aestivum L.) and maize ( Zea mays L.). The full impact of various rotation schemes on soil water balance through a sequence of seasons has not been explored, although the value of these rotations has been studied experimentally. The objective of this work was to investigate through simulations, potential differences in temporal soil water status among rotations over five years. In this study, mechanistic models of soybean (Soy), maize (Maz), and wheat (Wht) were linked over a five-years period at Marcos Juarez, Argentina to simulate soil water status, crop growth, and yield of four no-till rotations (Soy/Soy, Soy/Wht, Soy/Maz, and Soy/Maz/Wht). Published data on sowing dates and initial soil water contents in the first year from a no-till rotation experiment were used as inputs to the model. After the first year, soil water status output from the model was used to initiate the next crop simulation in the sequence. The results of these simulations indicated a positive impact on soil water balance resulting from crop residue on the soil surface under no-till management. Continuous soybean and the two-year soybean/maize rotation did not efficiently use the available water from rainfall. Residue from maize was simulated to be especially effective in suppressing soil evaporation. Thus, the Soy/Maz simulation results indicated that this rotation resulted in enhanced soil water retention, increased deep water percolation, and increased soybean yields compared with continuous soybean crops. The simulated results matched well with experimental observations. The three-crop rotation of Soy/Maz/Wht did not increase simulated soybean yields, but the additional water retained as a result of decreased soil evaporation resulting from the maize residue allowed the addition of a wheat crop in this two-year rotation. Simulated soybean yields were poorly correlated with both the amount of soil water at sowing and the rainfall during the cropping period. These results highlight the importance of temporal distribution of rainfall on final yield. These models proved a valuable tool for assessing the consequences of various rotation schemes now being employed in Argentina on temporal soil water status, and ultimately crop yield.
  • Authors:
    • Ciesiolka, C. A. A.
    • Ghadiri, H.
    • Yu, B.
    • Sanjari, G.
    • Rose, C. W.
  • Source: Soil Research
  • Volume: 47
  • Issue: 8
  • Year: 2009
  • Summary: The time-controlled rotational grazing (TC grazing) has become popular in Australia and elsewhere in the world to provide graziers and ranchers with improved productivity over traditional practices. However, this grazing system, which involves short periods of intensive grazing, has raised concerns about sustainability and environmental impacts on water and soil resources, and ecosystem health generally. A runoff experiment at the catchment scale was established on the grazing property 'Currajong' in the south-east region of Queensland, Australia, to investigate the effects of continuous and TC grazing on runoff and sediment generation from 2001 to 2006. Sediment loss was reduced significantly under TC grazing compared with continuous grazing irrespective of the size of runoff events. This effect was more pronounced in the catchments with soils of gentler slopes and greater depths. The reduction in soil erosion was achieved despite the fact that the increase in ground cover under TC grazing had little effect on runoff coefficient or runoff depth. Decrease in runoff in relation to the increase in surface cover only occurred for small events, whereas for large rainfall events, runoff generated irrespective of the level of ground cover. This study showed that ground cover is a key driver in reducing sediment concentration, resulting in a significantly lower sediment loss under TC grazing. In the study area a minimum of 70% of surface cover as a threshold appeared to be needed to efficiently protect the soil surface from erosive forces of rain and runoff and to control soil erosion. The results also indicate that TC grazing has a superior capability to produce and maintain a higher level of ground cover (up to 90%) than continuous grazing (up to 65%). The long rest periods in TC grazing are seen as the major contributor to soil and pasture recovery after intensive defoliations by grazing animals, leading to an increase in above-ground organic material and thus surface cover over time.
  • Authors:
    • Fontaneli, R. S.
    • Santos, H. P. dos
    • Spera, S. T.
    • Tomm, G. O.
  • Source: Revista Brasileira de Ciência do Solo
  • Volume: 33
  • Issue: 1
  • Year: 2009
  • Summary: Soil physical characteristics were evaluated of a typical dystrophic Red Latosol (Typic Haplorthox) located in Passo Fundo, State of Rio Grande do Sul, Brazil, after ten years (1993 to 2003) under mixed production systems. The effects of production systems integrating grain production with winter annual and perennial forages under no-tillage were assessed. Five mixed cropping systems were evaluated: (i) wheat/soyabean, white oat/soyabean, and common vetch ( Vicia sativa)/maize; (ii) wheat/soyabean, white oat/soyabean, and annual forages (black oat ( Avena nuda) + common vetch)/maize; (iii) perennial cool season forages (fescue ( Festuca) + white clover ( Trifolium repens) + red clover ( T. pratense) + birdsfoot trefoil ( Lotus corniculatus)); and (iv) perennial warm season forages (bahiagrass ( Paspalum notatum) + black oat + ryegrass ( L. perenne) + white clover + red clover + birdsfoot trefoil). System V lucerne as hay crop was established in an adjacent area in 1994. Half of the areas under the systems III, IV, and V returned to system I after the summer of 1996 (southern hemisphere). The crops, both summer and winter, were grown under no-till. The treatments were arranged in a randomized complete block design, with four replications. Soil core samples were also collected in a subtropical forest fragment adjacent to the experimental area. The variations in soil bulk density, total porosity, microporosity and macroporosity due to grain production systems with forages were not severe enough to cause soil degradation. The soil bulk density in the production systems with perennial forages was lower and total porosity and macroporosity, in the 0-2 cm layer, higher than in the production systems of grain or of grain with annual forages.
  • Authors:
    • Pérez, R.
    • Ayuso, J. L.
    • Taguas, E. V.
    • Yuan, Y.
    • Peña, A.
  • Source: Earth Surface Processes and Landforms
  • Volume: 34
  • Issue: 5
  • Year: 2009
  • Summary: Despite the high risk of erosion in olive Orchards located in mountainous areas in Spain, little research has been carried out to account for the complexity and interaction of the natural processes of runoff and soil erosion on the catchment scale or small catchment scale. In this Study, a microcatchment of 6.7 ha in a mountainous area under no-tillage farming with hare soil was Set Up to record runoff and sediment. Soil erosion and runoff patterns were monitored Over a two-year period. Totally events were observed. The data were analysed, and then Used to calibrate the, AnnAGNPS model, which allowed Lis to complete the data period and describe the hydrological and erosive behaviour on a monthly and annual basis. A high variability in catchment responses was observed, due to differences in the storms and to the effect of the surface Soil moisture content. Maximum intensities of 10 and 30 min determined the final runoff Values while the total sediment leads were dependent on the rainfall depth. The impact of management on the reduction of porosity can explain the relationship between runoff and intensity in the microcatchment. However, the impact of the spatial scale meant that the transport of sediment required substantial rainfall depths to ensure a Continuous flew front the hillslopes. The results of the calibration (E > 0.60 and r > 0.75) on the event and monthly scale confirmed the applicability of AnnAGNPS to predict runoff and erosion in the microcatchment. The predicted average runoff coefficient was 3.3% for the study period and the total average Sediment loads, 1.3 Mg/ha/yr. Despite these low Values, the model Simulation Showed that much larger runoff coefficients and soil losses can be expected for periods with several consecutive years in which the annual rainfall depth was over 500 mm). The use of cover is recommended to prevent the high levels of erosion associated with these conditions. Copyright (C) 2009 John Wiley & Sons, Ltd,
  • Authors:
    • Wall, P. C.
    • Thierfelder, C.
  • Source: Soil & Tillage Research
  • Volume: 105
  • Issue: 2
  • Year: 2009
  • Summary: The adoption of conservation agriculture (CA), based on minimal soil movement, permanent soil cover with crop residues or growing plants and crop rotation has advanced rapidly in the Americas and Australia over the last three decades. One of the immediate benefits of CA in dryland agriculture is improved rainfall-use efficiency through increased water infiltration and decreased evaporation from the soil surface, with associated decreases in runoff and soil erosion. This paper focuses on the effect of CA techniques on soil moisture relations in two researcher-managed trials in Zambia and Zimbabwe. In 2005/2006 and 2006/2007, we found significantly higher water infiltration on both sites on CA fields compared to conventionally ploughed fields. At Henderson Research Station, Zimbabwe, on a sandy soil, a direct seeded CA treatments had a 49% and 45% greater infiltration rate than the conventionally tilled plots after a simulated rainfall in both seasons. At Monze Farmer Training Centre, Zambia, on a finer-textured soil, the same treatment had 57% and 87% greater infiltration rate than the conventionally tilled control treatment in both seasons. Treatments that included reduced tillage and surface residue retention had less water runoff and erosion on runoff plots at Henderson Research Station, Zimbabwe. On average, soil moisture was higher throughout the season in most CA treatments than in the conventionally tilled plots. However, the full potential of CA in mitigating drought was not evident as there was no significant drought period in either season. Results suggest that CA has the potential to increase the productivity of rainfall water and therefore reduce the risk of crop failure, as was apparent at the Monze Farmer Training Centre, Zambia, in 2005/2006 when a period of moisture stress at tassling affected CA treatments less than the conventionally tilled treatment. (C) 2009 Elsevier B.V. All rights reserved.