Oat Cultivation Research Articles

Pre-sowing bacteria treatment and chemical fertilization application impact on productivity and yield quality of hulles (Avena nuda) and hulled oats (Avena sativa)

The questions of possibilities to increase oat productivity due to introduction of intensive growing technologies have been considered. It is defined that hulles oat (Avena nuda) cultivars have more expressed level of reaction on pre-sowing treatment with composition of Diazophyt and Microhumin preparations, that allows to get closer to hulled oat (Avena sativa L.) productivity indexes at the less doses of chemical fertilizers. The complex of oat reaction differences on basic growing factors is estimated that specifies on expediency of zonal growing technologies optimization of hulled and hulles oat cultivars. The maximum increase compared to control was noticed in variant with pre-sowing treatment Diazophyt + Microhumin composition in Salomon cultivar: 0.74 t/ha without the use of fertilizers and 0.73-0.75 t/ha in variants with basic application and different ways of fertilizers dressing. The highest yield (for all cultivars) provided variant with pre-sowing treatment Diazophyt + Microhumin composition and application of maximum fertilizer dose: N60P60K60 + Foliar nutrition Nutrivant Plus 2 kg / ha + Urea 46.2% 30 kg / ha in tillering and panicle ejection phases. In the conditions of the North-Eastern Forest-Steppe of Ukraine the parameters of vegetative development and productivity of oats cultivars revealed group dynamics on the change of pre-sowing treatment, doses and ways of fertilizer application. This makes it possible to consider the possibility of increasing crop productivity by improving oats cultivation technology in the context of hulles and hulled oat group of cultivars.

Rusle parameters for modeling the loss of a soil subjected to pig slurry application

Abstract: The objective of this work was to determine adjustment parameters for the revised universal soil loss equation (Rusle) of a soil subjected to pig slurry application. Treatments consisted of 0, 50, 100, and 200 m3 ha-1 pig slurry (PS), after the cultivation of black oat (Avena strigosa), besides the application of 50 m3 ha-1 PS for six times onto the soil surface in a temporal sequence, and a control treatment of soil without cultivation and without pig slurry application. The evaluations were performed for black oat shoot dry mass, root mass and crop residues semi-incorporated into the soil (RMR), soil losses by means of simulated rain, and the parameters for water erosion modeling. The pig slurry application onto soil surface caused a reduction in the values of the soil consolidation parameter (Cf), an increase in the mass of living and dead roots and cultural residues incorporated in the upper layer (0.0-0.1 m) of the soil (Bu), and a reduction in the subfactor prior land use (PLU) of the Rusle.

Multi-Environmental Trials Reveal Genetic Plasticity of Oat Agronomic Traits Associated With Climate Variable Changes.

Although oat cultivation around the Mediterranean basin is steadily increasing, its yield in these regions lags far behind those of Northern Europe. This results mainly from the poor adaptation of current oat cultivars to Mediterranean environments. Local landraces may act as reservoirs of favorable traits that could contribute to increase oat resilience in this region. To aid selection of suitable agro-climate adapted genotypes we integrated genome-wide association approaches with analysis of field assessed phenotypes of genetic variants and of the weight of associated markers across different environmental variables. Association models accounting for oat population structure were applied on either arithmetic means or best linear unbiased prediction (BLUPs) to ensure robust identification of associations with the agronomic traits evaluated. The meta-analysis of the six joint environments (mega-environment) identified several markers associated with several agronomic traits and crown rust severity. Five of these associated markers were located within expressed genes. These associations were only mildly influenced by climatic variables indicating that these markers are good candidates to improve the genetic potential of oat under Mediterranean conditions. The models also highlighted several marker-trait associations, strongly affected by particular climatic variables including high rain pre- or post-heading dates and high temperatures, revealing strong potential for oat adaptation to specific agro-climatic conditions. These results will contribute to increase oat resilience for particular climatic conditions and facilitate breeding for plant adaptation to a wider range of climatic conditions in the current scenario of climate change.

Odżywcze i prozdrowotne właściwości ziarna owsa i przetworów owsianych

W pracy przedstawiono krótką historię uprawy owsa, charakterystykę botaniczną, skład chemiczny ziarna, wartość odżywczą i prozdrowotną oraz wielostronne wykorzystanie. Owies i jego produkty są cennym źródłem wielu bioaktywnych składników odżywczych i substancji, takich jak: białka, lipidy, składniki mineralne, witaminy, błonnik pokarmowy, beta-glukany, polifenole. Owies jest zbożem o prozdrowotnym działaniu na organizm człowieka. Zdaniem żywieniowców i lekarzy, produkty owsiane mogą stanowić cenne uzupełnienie diety, zwłaszcza u osób z chorobami, takimi jak: zaburzenia czynności przewodu pokarmowego, miażdżyca, nadciśnienie, nadwaga czy obniżona sprawność psychofizyczna.

AGROECOLOGICAL EFFICIENCY OF SEWAGE SLUDGE AND VERMICOMPOST IN AGROCENOSES OF CULTIVATED OAT

Aim. The article suggests research on biotransformation of sewage sludge from treatment facilities in the city of Ryazan into organomineral fertilizer. An ecological analysis of the efficiency of fertilizer use in oat cultivation is proposed. Methods. Determination of growth and development indices of plants, structure of the oats crop of the Skakun variety, agrochemical indices of the soil. Results. Analyzed the effect of sewage sludge and vermicomposts, which are the basis for the cultivation of oats (Avena sativa) on organic soils (peat-mineral soil) which forms favorable conditions for the development of plants and the formation of high productivity of the crop, ensuring the production of ecologically safe grain products. Conclusion. The effect of the dehydrated sewage sludge and vermicomposts from the biological treatment plant in the city of Ryazan on the productivity of the Skakun oat has been revealed. The use of sewage sludge and vermicomposts is marked by an increase in the elements of the crop structure of the grain crop, as a consequence, by an increase in the bioproductivity of the phytocenosis, which indicates the advisability of using sewage sludge as a fertilizer.

Molecular and comparative mapping for heading date and plant height in oat

Selection of oat genotypes combining earliness and short plant height could stimulate oat cultivation worldwide. However, the mechanisms involved with the genetic control of heading date and plant height traits are not fully understood to date. This study aimed to identify genomic regions controlling heading date and plant height in two hulled by naked oat populations and to compare these genomic regions with that of other grass species. Recombinant inbred lines of each population and their parents were genotyped by a 6 K BeadChip Illumina Infinium array and assessed for heading date and plant height in two sowing dates. The quantitative trait loci (QTL) affecting these traits were detected by simple interval mapping. The two oat populations showed different genetic mechanisms controlling heading date. A major QTL was identified in one of the populations, mapped into the ‘Mrg33’ consensus linkage group from the current oat map. Two other QTL were detected into the ‘Mrg02’ and ‘Mrg24’ groups, in the second population. On the other hand, both populations presented the same genomic region controlling plant height. Six SNP markers, mapping on the same linkage group within each population, were associated with the trait, regardless the sowing date, explaining more than 20% of the phenotypic variation. Five of these six markers were mapped into three different linkage groups on the oat consensus map. Genomic regions associated with heading date and plant height in oat seem to be conserved in Oryza sativa L. and Brachypodium distachyon. Our results provide valuable information for marker-assisted selection in oats, allowing selection for earliness and plant height on early segregating generations.

Mogućnost suzbijanja korova združenim gajenjem jarog stočnog graška sa ovsem

Field pea is a high quality fodder crop of a short vegetation period. The production of field peas as a spring crop reduces the risk of yield losses due to unfavourable winter conditions, improves soil characteristics and ensures high quality fodder at the end of the spring. Intercropping with oats is often carried out due to the fact that field pea requires support and both species have similar developmental stages. The field experiment was set up at the Institute for Animal Husbandry in Zemun in 2017, in order to study the forage yield and the possibility of weed control by cultivating the mixture of field pea and oats. Serbian varieties of field pea NS Junior and oats cultivar Dunav were included in the trial, intercropped according to the 'additive model' in two ways: 100:15% and 100:30% pea : oats, when compared to monoculture (100% pea and 100% oats). In the 100:15% intercrop model of field pea and oats , the number of weed units and their fresh and dry weight were lower than in monocultures, while the higher presence of weeds in the 100:30% model was significantly affected by the high number and biomass production of weed species Ambrosia artemisiifolia. The cultivation of oats and field pea in the mixture significantly increased the yield of fresh and dry biomass, when compared to monocultures, while there was no significant difference in yield between the different methods of peas and oats (100:15% and 100:30%) intercropping. The higher share of oats at the crop establishment stage did not increase the forage yield, indicating the dominant contribution of the field pea biomass in the mixture.

INFLUENCE OF FARMING SYSTEM ON GREENHOUSE GAS EMISSIONS WITHIN CEREAL CULTIVATION

The emissions of greenhouse gases (GHG) from anthropogenic activities have still been a topical and much-discussed issue. In farming, room for reducing GHG emissions may also be available in crop farming. The measures aimed at the mitigation of GHG emissions may include a change in the farming system or partial switch to more extensive farming methods, including organic farming. The life cycle of oat, rye, wheat and spelt wheat cultivation in conventional and organic farming systems in the conditions of Central Europe was evaluated by LCA method, impact category: climate. The results clearly show that there are considerable differences between conventional and organic farming systems in individual subcategories of the farm phase of the production of cereals. The CO2e emissions produced in the cultivation of the monitored cereals are lower in organic farming systems, both when converted to an area unit and when converted to a production unit.

Совершенствование технологий возделывания овса в условиях Кировской области

The data of 2016-2017 studies on effectiveness of different oat cultivation technologies including ways of basic and pre-sowing soil tilling and using of bio-preparations on sod-podzolic soils of Kirov region are provided. Ploughing and surface soil tillage, cultivation and tilling with combined soil-tillage sowing machine, as well as preparation on the basis of S. hygroscopicus A4 strain and Pseudobacterin-2 were studied in the experiment. Storage of productive moisture in soil layer of 0-20 cm was 25.2-29.5 mm before sowing; there were no differences in the ways of soil tilling. The density of 0-20 cm soil layer was 0.05-0.06 g/cm 3 higher in variants with surface tillage. Application of combined aggregate APPN-2.1 provided “excellent” structure state of arable layer, the content of agronomical valuable particles was 82.284.4% at the soil structure coefficient equal to 4.7-5.5. Sowing dockage was significantly lower in variants of plowing (41.3 psc./m 2 , LSD 05 =2.8) than in surface tillage (44.5 psc./m 2 ). In variants with use of Pseudobacterin-2 preparation the sowing dockage increased too up to 50.1 psc. /m 2 (LSD 05 = 7.2) as compared to the variants without preparations (38.1 psc./m 2 ) and with the use of preparation on the base of S. hygroscopicus A4 strain (40.5 psc./m 2 ). Up to 31.6% of oat plants were affected with root rot in variants without preparations; by application of preparations on the base of S. hygroscopicus strain A4 the affection decreased to 11.3%; by application of Pseudobacterin-2 preparation - to 10.5% (LSD 05 = 3.9). The affection of oat plants with leaf rust was insignificant; the preparations significantly decreased this factor from 8.6 to 3.1-3.9% (LSD 05 = 1.7). On the average, for two years of study the highest productivity was noted in the variant of ploughing with using the combined sowing unit APPN-2.1 by application of preparation on the base of S. hygroscopicus strain A4 (1 l/ha) - 3.92 t/ha that is 1.01 t/ha higher then control variant, ploughing with KPS-4 pre-sowing tilling without preparations. The level of total profitability of oat grain production was 136.1%, the factor of energy effectiveness was 3.05 (in control variant - 84.4% and 2.34 correspondingly).

Evaluation of forage demonstrations to identify adoption gaps in oats production in limited water situations under RKVY project

A study conducted in North West region of Rajasthan among 66 farmers sampled from four districts namely, Bikaner, Sriganganagar, Sikar and Hanumangarh. Among the districts 22 villages were selected randomly and all respondents were possessing limited irrigation resources. Improved package of practices for oats cultivation were maintained regarding forage demonstrations. The study was conducted for three years ( i.e . 2011-12 to 2013-14) during Rabi season under RKVY project, governed by SKRAU, Bikaner and funded by Department of Agriculture and Farmer Welfare, GOI through Govt. of Rajasthan, Jaipur. Findings of the study revealed that increase in yield in demonstration plots due to adoption of improved package of practices was ranged between 31.6 to 55.56 per cent with mean per cent increase of 44.31% as compared to traditional practices of oats cultivation. In case of technology gap 154.50 q/ha overall mean difference was observed whereas 75.00 q/ha yield an average extension gap and a wide technology gap of 42.0 per cent was recorded as a result of difference between technology generated by the researchers and its adoption at the farmers fields. However, the overall adoption index increased from 7.00 to 46.70 per cent due to intervention of the project. Study further highlighted that the comparison of cost: benefit ratio between traditional practice and the adoption of improved practices indicated that demonstrations technology proved twice profitable as compared to existing traditional practices. While an overall increase adoption index noted were 3.5 to 49.8, 4.6 to 34.6, 12.9 to 49.81, 8.85 to 63.9, 4.9 to 34.2 and 7.3 to 48.4 per cent for the improved varieties, seed treatment, fertilizer and irrigation management, weed control and plant protection measures and cutting management practices, respectively.

Molecular variability of oat based on gene specific markers

Oat (Avena sativa L.) is a grass planted as a cereal crop. Cultivation of oat is increasing in the recent years because of its good nutrition value. The aim of our study was to analyze genetic variability of oat accessions based on SCoT markers. Eighteen primers were used to study polymorfism of 8 oat genotypes. All 18 primers produced polymorphic and reproducible data. Altogether 153 different fragments were amplified of which 67 were polymorphic with an average number of 3.72 polymorphic fragments per genotype. The number of polymorphic fragments ranged from one (SCoT9, SCoT62) to nine (SCoT40). The percentage of polymorphic bands ranged from 14.29% (SCoT9) to 60% (SCoT59) with an average of 41.62%. Genetic polymorphism was characterized based on diversity index (DI), probability of identity (PI) and polymorphic information content (PIC). The diversity index of the tested SCoT markers ranged from 0 (SCoT9, SCoT62) to 0.878 (SCoT40) with an average of 0.574. The polymorphic information content ranged from 0 (SCoT9, SCoT62) to 0.876 (SCoT40) with an average of 0.524. Dendrogram based on hierarchical cluster analysis using UPGMA algorithm grouped genotypes into two main clusters. Two genotypes, Taiko and Vok were genetically the closest. Results showed the utility of SCoT markers for estimation of genetic diversity of oat genotypes leading to genotype identification.

The agronomic performance and nutritional content of oat and barley varieties grown in a northern maritime environment depends on variety and growing conditions

Warmer temperatures and increasing interest in high provenance food and drink products are creating new opportunities for cereal growing in northern Europe. Nevertheless, cultivation of oats and barley in these areas for malting and milling remains a challenge, primarily because of the weather, and there are few reports of their nutritional content from this region. In this study, trials in Orkney compared agronomic characteristics and nutritional content of recommended UK oat and barley varieties with Scandinavian varieties over three years. For a subset of varieties, nutritional content was compared with samples cultivated in more southerly sites. For Orkney, barley was considered a more suitable crop than oats because varieties matured earlier. In both crops, Scandinavian varieties matured earlier than UK varieties and some produced comparable yields. The range of values for macronutrients and minerals in oats and barley in Orkney were similar to those reported previously for other locations, but there were some significant differences attributable to variety and year. Compared with grain samples from more southerly locations, oats in Orkney had a significantly lower β-glucan and higher sodium content. The lower β-glucan may have resulted from higher rainfall and lower temperatures during the months of grain filling and maturation.

Residual phosphate fertilization and Azospirillum brasilense in the common bean in succession to maize intercropped with Marandu grass

One of the alternatives for achieving sustainable agriculture and a reduction in production costs, especially with phosphate fertilisers, is to inoculate seeds with bacteria of the genus Azospirillum. The aim of this study therefore, was to evaluate residual phosphate fertilisation and Azospirillum brasilense, together with the contribution of straw from maize intercropped with Marandu grass, on leaf nutritional content, yield components and winter bean yield. The experiment was carried out on the Teaching and Research Farm, of the School of Engineering at UNESP, located in Selviria in the State of Mato Grosso do Sul, in a typic clayey dystrophic Red Latosol. The experimental design was of randomised blocks with four replications in a 5 x 2 factorial scheme. The treatments consisted of beans sown on straw from maize intercropped with Marandu grass on areas that had received five levels of P2O5 in the form of MAP, applied during an initial cultivation of black oats (0, 30, 60, 120 and 240 kg ha-1), both with and without inoculation of the oat and maize which preceded the beans with Azospirillum brasilense. Leaf nutrient content, leaf chlorophyll index (ICF), yield components and bean productivity were all evaluated. Inoculation with Azospirillum brasilense of the black oat and maize seeds improved the nutritional status of the plants, but had a negative effect on grain yield. Fertilisation of the oat crop with phosphorus had a positive residual effect on the beans, with increases in yield components and grain yield.

Association of swine wastewater and mineral fertilization on black oat production

Swine wastewater (SW) has high organic load, becoming an important source of macro and micronutrients to plants, promoting the improvement of soil quality and development in various cultures. However, when done without agronomic and environmental criteria, it can cause soil problems, nutrient leaching, water resource damage and plant toxicity. The objective of this study was to evaluate the soil chemical properties and the leachate in face of the association of swine wastewater and mineral fertilization (MF) in oat cultivation. An experiment in drainage lysimeter was carried out, using SW applications associated to MF or not, where treatments consisted of doses of 0, 100, 200 and 300 m3ha-1 with the absence or presence of MF, under field conditions. We concluded that swine wastewater provided significant increases in sodium, copper, zinc, and nitrite + nitrate as well as pH and calcium reductions in the soil; and in the leachate, significant increase in sodium. Moreover, the use of mineral fertilizer comprising nitrogen, phosphorus and potassium induced a significant increase in phosphorus, potassium and electrical conductivity and a significant reduction in magnesium in the soil; however, in the leachate, electrical conductivity was increased.

Population structure and genome-wide association analysis for frost tolerance in oat using continuous SNP array signal intensity ratios.

Key messageInfinium SNP data analysed as continuous intensity ratios enabled associating genotypic and phenotypic data from heterogeneous oat samples, showing that association mapping for frost tolerance is a feasible option.Oat is sensitive to freezing temperatures, which restricts the cultivation of fall-sown or winter oats to regions with milder winters. Fall-sown oats have a longer growth cycle, mature earlier, and have a higher productivity than spring-sown oats, therefore improving frost tolerance is an important goal in oat breeding. Our aim was to test the effectiveness of a Genome-Wide Association Study (GWAS) for mapping QTLs related to frost tolerance, using an approach that tolerates continuously distributed signals from SNPs in bulked samples from heterogeneous accessions. A collection of 138 European oat accessions, including landraces, old and modern varieties from 27 countries was genotyped using the Infinium 6K SNP array. The SNP data were analyzed as continuous intensity ratios, rather than converting them into discrete values by genotype calling. PCA and Ward’s clustering of genetic similarities revealed the presence of two main groups of accessions, which roughly corresponded to Continental Europe and Mediterranean/Atlantic Europe, although a total of eight subgroups can be distinguished. The accessions were phenotyped for frost tolerance under controlled conditions by measuring fluorescence quantum yield of photosystem II after a freezing stress. GWAS were performed by a linear mixed model approach, comparing different corrections for population structure. All models detected three robust QTLs, two of which co-mapped with QTLs identified earlier in bi-parental mapping populations. The approach used in the present work shows that SNP array data of heterogeneous hexaploid oat samples can be successfully used to determine genetic similarities and to map associations to quantitative phenotypic traits.Electronic supplementary materialThe online version of this article (doi:10.1007/s00122-016-2734-y) contains supplementary material, which is available to authorized users.

Management Options for Organic Winter Wheat Production under Climate Change

An effective adaptive strategy for reducing climate change risks and increasing agro-system resiliency is broadening cropping system diversity, heightening the flexibility of cultivation and tillage methods. Climate change impacts on standard cultivation practices such as mineralisation and nitrate leaching due to mild and rainy winters, as well as frequent drought or water saturation, not only limiting fieldwork days, but also restricting ploughing. This calls for alternative methods to counteract these propensities. From 2010 to 2013, a farming system experiment was conducted on a distinctly heterogeneous organic farm in Brandenburg, Germany. With the intention of devising a more varied and flexible winter wheat cultivation method, standard organic farming practices (winter wheat cultivation after two years of alfalfa-clover-grass and ploughing in mid-October) were compared to four alternative test methods, which were then evaluated for their robustness and suitability as adaptive strategies. Two of the alternative methods, early sowing and catch crop , entailed moving up the date for alfalfa-clover-grass tilling to July. Instead of a plough, a ring-cutter was used to shallowly (8 cm) cut through and mix the topsoil. In the early sowing test method, winter wheat was sown at the end of August, after repeated ring-cutter processing. With the catch crop method, winter wheat seeding followed a summer catch crop and October tillage. The two oat methods ( oat/plough ; oat/ring-cutter ) entailed sowing winter wheat in September, following oat cultivation. Overall, the cultivation methods demonstrated the following robustness gradation: standard practice = catch crop ≥ early sowing > oat/plough > oat/ring-cutter . When compared to standard procedures, the catch crop and early sowing test methods showed no remarkable difference in grain yields. Measured against early sowing , the catch crop test method was significantly more robust when it came to winterkill, quality loss, and weed infestation (40% lower weed-cover). High N min- values (up to 116 kg N ha -1 ) in autumn could have caused the chamomile and thistle infestation in both oat/plough oat/ring-cutter test methods, which led to crop failure in the hollows. Compared to standard practices, the oat ring-cutter test method brought in over 50% less grain yield. This was attributed to ring-cutter processing, which reduced N mineralisation and caused high weed infestation. However, the ring-cutter effectively regulated alfalfa-clover-grass fields in both exceedingly wet and very dry weather; a temporal flexibility which increases the number of fieldwork days. The catch crop and early sowing test methods contributed most to boosting future agronomic diversity.

Environmental and economic aspects of Triticum aestivum L. and Avena sativa growing

AbstractThis paper deals with the assessment of cultivation of bread wheat (Triticum aestivum L.) and oat (Avena sativa) grown in Central Europe within the conventional and organic farming systems in terms of greenhouse gas emissions and economic profitability. Organic farming may be one of the tools for mitigation of greenhouse gas emissions from agricultural production. In the context of crop production, cereals rank among the most commonly grown crops and therefore bread wheat and oat were chosen. The Climate change impact category was assessed within the simplified LCA method and the production of greenhouse gas emissions expressed in CO2e per the production unit was calculated. Economic balance of the cultivation of monitored cereals was compiled based on the yields, farm gate prices and costs. On its basis, the cultivation of wheat within the organic farming system appears to be the most profitable. From an environmental point of view, the emission load of the organic farming system is reduced by 8.04 % within the wheat production and by 15.46 % within the oat cultivation. Therefore, the organic farming system in the Czech Republic appears to be more environmentally friendly and economically efficient within the cereals production.

Classification of plant species from images of overlapping leaves

Automatic identification of plant species is needed in precision agriculture in order to collect species information and guide sprayers of agrochemicals. Identification methods based on spectroscopic properties, leaf forms and chlorophyll fluorescence have been developed. Leaf overlap is a major difficulty and most of the proposed methods only operate on isolated leaves. The present study focused on the leaf overlap problem by analysing colour photographs of a mixed cultivation of oat (Avena sativa) and a dicot weed (dandelion, Taraxacum officinale, TAROF). Leaves of the two species appeared to have very similar colours and therefore species identification was based on the different textures of monocot and dicot leaves. An automatic classifier, based on the RankRLS learning algorithm, was developed in the study and trained with manually labelled parts of the photographs. We adopted a strategy in which the misclassification of oat pixels to TAROF was avoided at the expense of classifying most TAROF pixels as oat. This strategy is appropriate when the aim of the automatic identification is to guide a herbicide sprayer. In photograph-wise cross-validation, the misclassification of oat as TAROF was negligible and considerably smaller than the expected amount of misclassifications, indicating that leaf texture is useful for identification of plant species in this very demanding case.

Impact of nutrient losses from agricultural lands on nutrient stocks in Dianshan Lake in Shanghai, China

The water quality of Dianshan Lake in Shanghai Municipality, China, is impacted by nutrient losses from agricultural lands around the lake. In this study, nine types of agricultural land use were monitored in 2010 and 2011, and a correlation analysis between nutrient losses from agricultural non-point sources (NPS) and nutrient stocks in the lake was conducted over monthly and seasonal time periods. The results indicate that the monthly average concentration of total nitrogen (TN) ranged from 1.41 to 7.34 mg/L in 2010 and from 1.52 to 5.90 mg/L in 2011, while the monthly average concentration of total phosphorous (TP) ranged from 0.11 to 0.26 mg/L in 2010 and from 0.13 to 0.30 mg/L in 2011. The annual loss of TN from agricultural NPS was 195.55 tons in 2010 and 208.40 tons in 2011. The cultivation of water oat made the largest contribution to the loss of TN. The annual loss of TP was 44.58 tons in 2010 and 48.12 tons in 2011, and multi-vegetable cultivation made the largest contribution to the loss of TP. The results of correlation analysis show that the monthly stocks of TN and TP in the lake have a positive correlation with the monthly losses of TN and TP from agricultural NPS. According to the seasonal data, the stocks of TN and TP in the lake both have a much stronger correlation with the losses of TN and TP from agricultural NPS in summer than in other seasons. Agricultural NPS pollution control should be the main focus for the water resource conservation in this area.

English

The effects of different species and grazing management of winter forage crops on the physical properties of a clayey Red Latosol of the western region of Parana State under crop-livestock integration systems were investigated in the present study. Treatments consisted of three different winter crops [white oat (Avena sativa), dual-purpose wheat (Triticum aestivum) and triticale (X Tritico secale)] and three grazing management (one and two grazing with 15 cm of residue height, and without grazing), followed by soybean cultivation, in a randomized block design. Undisturbed soil samples were collected at 0.00-0.10 and 0.10-0.20 m depths, after the winter crops harvest (October/2012) and soybean harvest (March/2013) and was determined the soil bulk density until 0.35 cm depth. The soil macroporosity in the 0.00-0.10 and 0.10-0.20 m soil layers and the total soil porosity in the 0.10-0.20 m layer, after winter crops harvest, were influenced by the crops and management of winter forage. In the evaluation performed after the soybean harvest, there were changes in the soil macroporosity in the 0.0-0.10 m layer and for microporosity and total soil porosity in the 0.10-0.20 m soil layer. The soil bulk density was not affected by the crops and management of winter forage. The different species and grazing management of winter crops in integrated crop-livestock systems promoted changes in soil penetration resistance in the 0.20-0.30 m soil layer. The cultivation of white oat during winter and management with two grazing resulted in lower soil penetration resistance levels.   Key words: Physical quality, soil structure, soil penetration resistance, conservation cropping systems.