Effect of crop rotations soil quality, production, and economic returns of barley grown under zero till in Parana (Brazil)

Non-Peer ReviewedThe cereal growing area of southern Brazil is characterized by high intensity rainstorms, warm temperatures, hilly topography, and acid soils low in natural fertility. Traditionally, cereals are grown in winter in a double cropping system with soybeans grown in summer. These factors combined with excessive use of disc-type implements causes severe soil loss by water erosion, low grain yields due to disease and insects, and general soil degradation. The combined use of zero or minimum tillage with crop rotations which include other crop types is one solution being examined with assistance from CIDA and involving scientists from Canada and Brazil. This paper reports on the agronomic and economic performance of four zero-till barley rotations. After four years of study, the results show the beneficial effects of extending rotation lengths to break disease cycles as shown by improved barley yields. The choice of cropping sequence, however, significantly influences subsequent grain yields. While barley yields were highest for the 2-year and 4-year rotations and lowest for the barley-soybean rotation, net returns were generally highest for the 4-year and continuous barley systems. Soil properties such as organic matter, pH, and Al concentration did not change significantly with the use of extended rotations, however, the potential for soil erosion was reduced by use of zero-tillage management

The agro-industrial system regional sustainable development, a coherent strategy

The agro-industrial system represents annually circa 3,6 x 109 € in the formation of the Centro Region of Portugal gross income and that accounts for 39% of the Portuguese overall return for this sector. Given this dynamics it is of utmost importance to perform a consistent strategy to promote the sustainable growth of this regional system income. Therefore, the CERNAS/IPC research unit has developed an integrated approach bringing together several regional actors under a networking logic that links the industrial needs with the academia R&D capabilities, and of capacity building and entrepreneurship (2011-2013). This strategy is rooted in the InovCluster, where CERNAS leads two anchor projects, the in_AGRI and the ECODEEP, and collaborates with a third one, the AGRITRAINING. The in_AGRI aims the upgrade of the system value chains by bridging the academia with the industry in a series of workshops, supported with a knowledge transfer platform and a network of research facilities, and ECODEEP will develop eco-efficiency tools, based on a LCA approach to enhance the overall sustainability by improving practises and find new solutions within an industrial ecology framework. The AGRITRAINING surveys the training needs of the system, looking forward to complement the actual capacity building achieved by the Master courses in Food Engineering and Environmental Management. In addition, an advanced training in Environmental Entrepreneurship is being implemented, and an Innovation Management for SME’s program is being designed, promoting a cultural change towards the sustainable welfare of our present and future generations.InAGRI – Proj. n.º 3494 (Mais Centro/PORC); EcoDeep – Proj. n.º 18643 (SIAC/COMPETE/POFC); InovEnergy– Proj. n.º 18642 (SIAC/COMPETE/POFC); Agritraining – Proj. n.º 8310 (SIAC/COMPETE/POFC); GovCluster –Proj. n.º 8063 (SIAC/COMPETE/POFC

Efeito de concentrações de macronutrientes N, P e K No aumento do espessamento da parede dos traqueídos Pinnus Elliottii (plantas em vasos)

In this paper the authors present the results of the effect of the macronutrients nitrogen, phosphorus and potassium in the increase of fiber length and the thickness of the cell wall in Pinnus elliottii. The statistical analyses shows that higher levels of N seemed to decrease both length of fiber elements and the thickness of the wall. The effect of P and K were not well defined.Neste trabalho os autores apresentam os resultados dos efeitos dos níveis de N, P e K no aumento do comprimento e da espessura da parede dos traqueídos de Pinnus elliottii. A análise estatística mostra que alto nível de N parece indicar uma diminuição no comprimento e na espessura dos traqueídos, enquanto que os efeitos do P e K não se mostram bem definidos, provàvelmente por se tratar de material muito jovem, com apenas dois anos de idade, sob efeito dos tratamentos

The relation of the concentration of macronutrients in the substrate and in the foliage to cell wall thickness and cellulose concentration in the xylem of slash pine (Pinus elliotti)

Sand culture experiments, using a sub-irrigation technique, were installed in order to find out the effects of the macronutrients N, P, K, Ca, Mg and S on growth, aspect, mineral composition, length of fibers, thickness of cell wall and cellulose concentration in slash pine. The aim was to obtain, under controlled conditions, basic information which could eventually lead to practical means designed to increase the rate of growth and to make of slash pine a richer source of cellulose. Nitrogen, Phosphorus, Potassium Experiment A 3 x 3 x 3 factorial design with two replicates was used. Nitrogen was supplied initially at the levels of 25, 50 and 100 ppm; phosphorus was given at the rates of 5, 10 and 20 ppm; potassium was supplied at the rates of 25, 50 and 100 ppm; six months after the experiment was started the first level for each element was dropped to zero. Others macro and all micronutrients were supplied at uniform rates. Fifteen hours of illumination per day were provided. The experimental technique for growing the slash pine seedlings proved quite satisfactory. Symptoms of deficiency of nitrogen, phosphorus and potassium were observed, described and recorded in photographs and water colors. These informations will help to identify abnormalities which may appear under field conditions. Chemical analysis of the several plant parts, on the other hand, give a valuable means to assess the nutritional status of slash pine, thus confirming when needed, the visual diagnosis. The correctness of manurial pratices, on the other hand, can be judged with the help of the analytical data tabulated. Under the experimental conditions nitrogen caused the highest increases on growth, as measured by increments in height and dry weights, whereas the effects of phosphorus and potassium were less marked. Cellulose concentration was not significantly affected by the treatments used. Higher levels of N seemed to decrease both length of fiber elements and the thickness of cell wall. The effects of P and K were not well defined. Calcium, Magnesium, Sulfur Experiment A 3 x 3 x 3 factorial design with two replicates was used. Calcium was supplied initially at the levels of 12.5, 25 and 50 ppm; magnesium and sulfur were given at the rates of 6, 12.5 and 25 ppm. Other macro and micronutrients were supplied at uniform rates, common to all treatments. Three months after starting the experiment the first level for each element was dropped to zero. Symptoms of deficiency of calcium, magnesium and sulfur were observed, described and recorded as in the case of the previous experiment. Chemical analysis were made, both for mineral content and cellulose concentration. Length of fibers and thickness of cell wall were measured. Both calcium and magnesium increase height, sulfur failing to give significant response. Dry weight was beneficially affected by calcium and sulfur. The levels of calcium, magnesium and sulfur in the needles associated with deficiency and maximum growth are comparable with those found in the literature. Cellulose concentration increased when the level of sulfur in the substrate was raised. The thickness of cell wall was negatively affected by the treatments; no effect was observed with regards to length of fibers.Foram conduzidos experimentos fatoriais cultivando P. elliottii em solução nutritiva destinados a estudar o efeito de macronutrientes na composição mineral, grossura da parede celular e concentração da celulose no xilema. Os sintomas de deficiencia dos elementos foram descri tos e registrados. O crescimento foi estimulado por N, P, K, Ca e Mg, sendo a maior resposta devida ao N. Somente o enxofre aumentou significativamente o teor de celulose. A grossura da parede celular diminuiu com altos níveis de N, Ca, Mg e S; os primeiros diminuiram o comprimento das fibras

Transpiration reduction as an answer to water stress: models versus measurements for irrigated olive trees in South Portugal

The so-called stress functions, allowing quantification of transpiration or evapotranspiration reduction, as an answer to water deficit stress (stress coefficient, Ks), are useful tools for irrigation scheduling. It is known that this coefficient depends on several variables and parameters, such as evapotranspiration rate, root patterns/density and soil properties. However, the most common Ks models with practical applicability do not include some of these factors and the experimental work on this matter is not abundant. A well-known model proposed in the FAO 56 manual uses two parameters: the allowable depletion (p) and the total available soil water (TAW) in the root zone, the input variable being the soil water depletion (SWD). We discuss the application of this model in olive trees under specific natural conditions. Two studies were conducted in Alentejo, South Portugal (2011 and 2017), in one intensive and one super intensive drip irrigated olive orchards (Olea europaea 'Arbequina'). Transpiration reduction was obtained from sap flow measurements. For both experiments, Ks was related to the estimated SWD. The experimental relationship was compared with modelling outputs. Experimental results show that, in both experiments, the Ks FAO 56 model only fits using parameters such as p= 0.05 and TAW = 350 mm. The suggested p in that manual is 0.7. Furthermore, for such soils, anisotropic canopy and small wetted area (drippers), 350 mm is much more than first approach estimates would suggest. The results can be related with the root system functioning and resilience of olive treesinfo:eu-repo/semantics/publishedVersio