Rational Use Of Fertilizers Research Articles

Potassium nutrition in the first and second ratoon sugarcane grown in an Oxisol by a conservationist system

The presence of mulch on the soil surface after the mechanical harvesting of sugarcane (Saccharum officinarum L.) enhances the cycling of nutrients, especially K, which can decrease K fertilizer recommendations for the crop. The aim of this study was to evaluate the effect of K addition to an Oxisol, with an initial concentration 0.07 cmolc K kg-1, in first and second ratoon (no-till) sugarcane cultures by a conservationist system, i.e. rational use of fertilizers, use of alternative inputs and especially the maintenance of residues in soil that was previously burned to facilitate cutting. The following K doses were tested: 0, 32.5, 65, 130, and 195 kg K2O ha-1, arranged in a randomized block design with five replicates. Potassium content in the soil and in the plant, as well as the yield and the quality of stalks were evaluated. Soil K application increased K concentration in soil and plant, and was reflected in the production of stalks, with higher production (87.5 and 107.5 t ha-1) with the use of 120 and 123 kg K2O ha-1 in first and second ratoon sugarcane, respectively. At the first 2 yr it was not possible to reduce the K fertilization in ratoon. Therefore, with the introduction of the conservationist system there was an increase (20 t ha-1) at the second ratoon regarding the first one with the same applied rate.

Composição mineral de folhas de Oliveira (Olea europaea L.) em sistema de produção convencional

Objetivou-se com este trabalho quantificar a composição mineral das folhas de Oliveira a fim de diagnosticar o estado nutricional das plantas cultivadas em sistema convencional. O experimento foi conduzido com sete cultivares Arbequina, MGS Asc 315, MGS Mariense, MGS Grap 541, MGS Grap 561, Grappolo 575 e Leccino, em blocos casualizados com 4 repetições e parcelas com cinco plantas. Em maio de 2010 foram coletadas 60 folhas de cada cultivar (12 por planta) e submetidas a analise foliar. As cultivares apresentaram diferenças significativas entre si quanto aos teores foliares médios de nutrientes. Observou-se também que apesar da analise de solo apontar níveis elevados de Fe e Mn, a análise foliar acusou deficiência para esses elementos em todas as cultivares de Oliveira avaliadas. Os resultados alertam para os altos níveis de Cu, como consequência do uso abusivo de fungicidas a base de oxicloreto e calda bordalesa nos pomares. A concentração elevada desse elemento nas folhas pode causar fitotoxidez às plantas. Desta forma, sugere-se o uso racional de fertilizantes e de produtos fitossanitários no cultivo da oliveira a fim de evitar fitotoxidez ou deficiências nutricionais.

Using hyperspectral remote sensing techniques to monitor nitrogen, phosphorus, sulphur and potassium in wheat (Triticum aestivum L.)

In situ, non-destructive and real time mineral nutrient stress monitoring is an important aspect of precision farming for rational use of fertilizers. Studies have demonstrated the ability of remote sensing to monitor nitrogen (N) in many crops, phosphorus (P) and potassium (K) in very few crops and none so far to monitor sulphur (S). Specially designed (1) fertility gradient experiment and (2) test crop experiments were used to check the possibility of mineral N–P–S–K stress detection using airborne hyperspectral remote sensing. Leaf and canopy hyperspectral reflectance data and nutrient status at booting stage of the wheat crop were recorded. N–P–S–K sensitive wavelengths were identified using linear correlation analysis. Eight traditional vegetation indices (VIs) and three proposed (one for P and two for S) were evaluated for plant N–P–S–K predictability. A proposed VI (P_1080_1460) predicted P content with high and significant accuracy (correlation coefficient (r) 0.42 and root means square error (RMSE) 0.180 g m−2). Performance of the proposed S VI (S_660_1080) for S concentration and content retrieval was similar whereas prediction accuracies were higher than traditional VIs. Prediction accuracy of linear regressive models improved when biomass-based nutrient contents were considered rather than concentrations. Reflectance in the SWIR region was found to monitor N–P–S–K status in plants in combination with reflectance at either visible (VIS) or near infrared (NIR) region. Newly developed and validated spectral algorithms specific to N, P, S and K can further be used for monitoring in a wheat crop in order to undertake site-specific management.

Продуктивность озимой пшеницы сорта Казанская 560 в зависимости от удобрений и элементов питания в почве

The article discusses the influence of the main fertilizer in combination with additional fertilizing on the feeding regime of soil and productivity of “Kazanskaya 560” winter wheat variety. The provision of soil with available nutrients is achieved through the rational use of fertilizers in crop rotations. In 2010-2012 an additional fertilizing by Humate “Bioplant Flora” at a rate of 2 litre per hectare in autumn increased yield to 4.6-5.5 centner per hectare, depending on the background of the basic fertilizer. Additional spring fertilizing in early plant growth by Bioplant Flora on the background of autumn feeding practically does not increase the yield of winter wheat. Fertilizing with ammonium nitrate at a rate of 1.5 center in share weight per hectare increased the average yield to 2.1-2.4 tons per hectare for the period 2010-2012, depending on the background of the main treatment. In favorable 2011 it increased the yield to 1.5-3.5 centner per hectare. Adding NPK at sowing in rows at 1 centner per hectare in share weight increases yields to 3.5 centner per hectare without feeding, to 7.5 centner per hectare with the autumn fertilizing by Bioplant Flora, to 5.6 centner per hectare with the spring fertilizing with ammonium nitrate, comparing with the background without fertilizers. Thus, the differential application of the basic fertilizer, combined with fertilizing, improves the soil nutrient status and facilitates the formation of a predetermined amount of yield.

The role of antioxidant enzymes in adaptive responses to sheath blight infestation under different fertilization rates and hill densities.

Sheath blight of rice, caused by Rhizoctonia solani, is one of the most devastating rice diseases worldwide. No rice cultivar has been found to be completely resistant to this fungus. Identifying antioxidant enzymes activities (activity of superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT)) and malondialdehyde content (MDA) responding to sheath blight infestation is imperative to understand the defensive mechanism systems of rice. In the present study, two inoculation methods (toothpick and agar block method) were tested in double-season rice. Toothpick method had greater lesion length than agar block method in late season. A higher MDA content was found under toothpick method compared with agar block method, which led to greater POD and SOD activities. Dense planting caused higher lesion length resulting in a higher MDA content, which also subsequently stimulated higher POD and SOD activity. Sheath blight severity was significantly related to the activity of antioxidant enzyme during both seasons. The present study implies that rice plants possess a system of antioxidant protective enzymes which helps them in adaptation to sheath blight infection stresses. Several agronomic practices, such as rational use of fertilizers and optimum planting density, involved in regulating antioxidant protective enzyme systems can be regarded as promising strategy to suppress the sheath blight development.

NITROGÊNIO: NUTRIENTE OU POLUENTE?

The rational use of fertilizers, especially nitrogen in search of productivity growth, has been gaining increasing importance in activities related to Brazilian agriculture. However, for this goal is reached, it is necessary a more comprehensive understanding of the various factors affecting the efficient use of fertilizer. In turn the areas used for agricultural cultivation worldwide fertilizers contain too much or less. And the two extremes imply high costs for both the environment and man himself. One of the most limiting nutrient for crop production is nitrogen (N). Some poor people are starving in the world simply because there is a sufficient amount of N to adequately feed their crops. On the other hand, in certain regions of our planet, there is an excess of N. That is, this nutrient is supplied to crops in a much larger amount than necessary. In these situations, the N becomes a pollutant because its presence in excess triggers a series of reactions and processes that are extremely harmful to the environment and thus the health of populations. In order to understand the dynamics of N and how it can become pollutants carried to the present work.

Variabilidade de nutrientes em plantas de milho cultivado em talhão manejado homogeneamente

O conhecimento da variabilidade da nutrição de plantas e da produtividade em áreas cultivadas pode fornecer importantes subsídios na racionalização do uso de insumos e auxiliar no manejo da fertilidade do solo. O objetivo deste trabalho foi avaliar a variabilidade da nutrição mineral de plantas de milho por meio do fracionamento de um talhão cultivado comercialmente em células de manejo e verificar as relações com a produtividade. O estudo foi realizado na Fazenda Alto Alegre, em Planaltina (GO), em área de 373 hectares de Latossolo Vermelho-Amarelo Distroférrico, cultivado com milho na safra 2003/04. Traçado um polígono da área, procedeu-se sua divisão em 80 células de manejo de quatro hectares cada uma. A amostragem de folhas em cada célula seguiu uma diagonal com 12 pontos para compor uma amostra composta. Realizou-se a análise dos macro e micronutrientes nas folhas. A produtividade para cada célula foi obtida por meio de colhedora equipada com GPS. Na análise da variabilidade dos resultados foram considerados os parâmetros estatísticos descritivos. O teste ausência de correlação foi realizado com o nível de significância de 5%. A variabilidade da concentração dos nutrientes na folha indicadora do milho foi considerada baixa para N, P, K, S e Mg; e média para Ca, Cu, Fe, Mn e Zn. A variabilidade da produtividade de milho revelou diferenças de produção para cada célula analisada. Os coeficientes de correlação entre os nutrientes e a produtividade foram significativamente diferentes de zero (p<0,05) e negativos para Cu, Mn e Zn.

Usefulness of Foliar Nitrogen-Sulfur Ratio in Spring Red Wheat

ABSTRACT Sulfur (S) availability indicators are necessary for a rational use of fertilizers. Experiments were carried out to evaluate the sensitivity and stability of nitrogen (N):S ratio in spring red wheat. Yield responses were determined in three replications over five experimental sites. Sulfur application did not increase N concentration in plant, whereas the effect on total S concentration was varied. Results showed 25, 35, 80, and 85% correctly diagnosed samples at stages Z22, Z24, Z31, and Z39, respectively. In treatments without S limitations, a decrease in N:S ratio was observed as the crop cycle advanced. Nitrogen: S ratio differed according to the site; however, these variations tend to decrease as the crop cycle advance. In summary, for spring red wheat, N:S ratio in plant is a useful method for S deficiencies diagnostic from the end of tillering to flag leaf.

Effect of lodging on the level of mycotoxins in wheat, barley, and rice infected with the Fusarium graminearum species complex

Lodging is one possible risk factor that leads to increased cereal mycotoxin contamination, but few reports have been published on the subject. We examined the effects of lodging on the level of deoxynivalenol (DON) and nivalenol (NIV) contamination in wheat, barley, and rice infected with the Fusarium graminearum species complex. Case-control and intervention studies were applied to test the hypothesis that lodging increases the level of mycotoxin contamination. A total of 66 grain samples were collected from each field in 12 Japanese prefectures from 2002 to 2006. Each sample set consisted of grains from lodged and nonlodged plants. The concentration of DON + NIV in lodged plants was significantly higher than in nonlodged plants. All samples of wheat and barley were contaminated with DON and NIV; however, most of the lodged rice samples were contaminated only with NIV. In intervention trials to investigate the effects of lodging duration, a small area of wheat inoculated with the pathogen was completely lodged by trampling. Even with 5 days of lodging, the levels of DON + NIV in wheat grain at harvest increased by 27–51% compared to nonlodged control plots. For rice, half of each plot area was completely lodged by trampling 20 days before harvest. The level of NIV in lodged rice grain was significantly higher than that in nonlodged rice at optimum and delayed harvests, because lodging significantly increased the level of Fusarium mycotoxins in the three crops. Thus, practices (e.g., rational use of fertilizers) to avoid lodging should reduce the risk of mycotoxin contamination. This is the first epidemiological study on the effect of lodging on mycotoxin production by the F. graminearum species complex in wheat, barley, and rice.

Application of Soil and Plant Analysis for Applied Research and Development in West Asia–North Africa: An International Center's Perspective

The networks of 15 international research centers around the globe that are sponsored by the Consultative Group for International Agricultural Research (CGIAR) seeks to alleviate poverty in the developing world through enhanced production, while maintaining biodiversity and the sustainability of natural resources. The mandate of the International Center for Agricultural Research in the Dry Areas (ICARDA) is to focus on improving semi‐arid cropping systems in the drought‐prone West Asia and North Africa region. Since its inception in 1997, ICARDA's soil laboratory played a pivotal role in backstopping the institution's on‐station and on‐farm research in Syria and its collaborative research with the region's national programs. This article gives an overview of the evolution of soil and plant analysis in serving the center's mission. A major effort was the regional soil test calibration program, which set the basis for rational use of fertilizers and the identification of related nutrient constraints. Such analyses were extensively employed in all the long‐term dryland cropping system trials and later in irrigated agriculture and the interface between plant nutrition and crop breeding. Major emphasis was given to improving and upgrading analytical services in the region's laboratories. Despite advances made in analytical methodology, the challenge is to apply to solving real problems in the service of humanity.

Determining fertilizer phosphorus requirement of upland rice

Assessing the fertilizer phosphorus requirement (FPR) of crops is an important component of research for efficient and rational use of fertilizers. Soil and plant tests are used to determine the FPR of crops. Two methods were evaluated for determining the FPR of upland rice grown on an Ultisol in the humid forest zone of Cote d'Ivoire. The first method used a simple model based on P uptake using the equation: FPR=(Up‐U0)/PRF, where Up is P uptake at a given yield, Uo is P uptake from unfertilized soil, and PRF is the P recovery fraction of applied P. The parameters, U0, Up, and FPR were determined in field experiments for the rice cultivars grown on an Ultisol under rainfed upland conditions. The second method was based on the P applied, P uptake, and grain yield relationships for upland rice. First, P uptake at a given rice yield was determined from the relationship between total P uptake and grain yield. The amount of fertilizer P applied for the given P uptake and grain yield was then, determined from the relationship between P applied and P uptake. There was a good agreement between the observed values of FPR and the predicted values of FPR determined by the two methods. The results suggest that the simple model based on P uptake can be utilized for determining the fertilizer P requirements of crops.

Assessing the fertilizer phosphorus requirement of grain sorghum

Assessing the fertilizer phosphorus (P) requirements (FPR) of crops is an important component of research for efficient and rational use of fertilizers. Soil and plant tests are employed to determine the FPR. Two methods were evaluated for determining the FPR of sorghum grown on a Vertisol under rainfed conditions. The first method was based on P on applied P uptake, and grain yield relationships for grain sorghum. In this method, P uptake at a given yield was determined from the relationship between total P uptake and grain yield. The amount of fertilizer P applied for the given P uptake and grain yield was then, determined from the relationship between P applied and P uptake. In the second method, FPR was determined using the equation: FPR=(Up‐U0)/PRF, where Up is P uptake at a given yield, U0 is P uptake from unfertilized soil, and PRF is the recovery of applied P. The parameters, U0, Up, and PRF were determined in a field experiment with sorghum grown on a Vertisol under rainfed conditions. There was a good agreement between the observed value of FPR and predicted values determined by the two methods. These results suggest that the simple models based on P uptake can be utilized for determining the fertilizer requirements of crops.

La consommation d'engrais azotés en France. Une prospective pour 2010

The French nitrogen fertilizer consumption. Prospects for 2010. The protection of the environment is nowadays a major goal for our society and its importance will probably get highly amplified in the near future. Farmers are pointed at because, through their use of fertilizers, they are responsible for a diffuse pollution of rivers andphreatic sheets. At the same time, these farmers are facing economic difficulties due to the steady decrease of agricultural prices in the European Community. Therefore, they try to reduce production costs by a better management of their intermediate consumptions (mostly fertilizers). Given this context, ivhat will be in fifteen years the consumption of fertilizers in France ? The aim of this paper is to answer this question by studying several scenarii based on the evolution of the economical, political and technological context. The future Common Agriculture Policy will certainly be the factor that will most affect this evolution. We focus only on nitrogen fertilizers, which are supposed to be the main responsibles for the pollution of phreatic sheets and which use can be rationalized. Hoivever, the methodology used to determine future consumption is easily applicable to other inputs (potassic and phosphoric fertilizers, phytosanitary, seeds, energy...). The goal of this research is tivofold : * On the one hand, we build a prospective model representing the agricultural sector and the fertilizer industries in order to estimate (by simulations) the fertilizer consumption in 2010. No existant methodology can readily be used. We propose a methodology drawing on Yves Barel's thinking (1971) and on systemic analysis, that implies the interaction of modelling, expertizing and simulations. We apply it to the agriculture sector and to the fertilizer industry but it is applicable to other sectors. * On the other hand, in addition to punctual results, this research aims at drawing a global prospective design of the French agriculture sector in 2010. The results of our prospective study show that, by the year 2010, the consumption of nitrogen fertilizers should clearly decrease. Such a decrease is mainly explained by a more rational use of fertilizers by farmers, due to the increased "environmentalists" pressure, ivhose lobby is represented at Bruxelles and in each French administrative region. Relevant technological innovations are spreading and should help farmers improve their fertilizing techniques.

Impact of human activities on the quality of river water: The case of Evrotas River catchment basin, Greece

The impact of point (domestic and industrial effluents) and non-point (agricultural land runoff) pollution sources on the quality of the receiving waters of the Evrotas River (Laconia, Greece) was investigated during a monitoring study from August 1991 to August 1992. The part of the river which was located near the city of Sparta was seasonally influenced by the discharge of effluents from orange juice plants (operating during winter) and by the discharge of septage for the emptying of cesspools which are serving part of the city. The low dilution of incoming pollutants (septage) during the low water flow in summer lead to the decreasing self-purification capacity of the river and the development of septicity conditions in some of its parts. In the vicinity of intensively cultivated areas, the high concentrations of nitrogen and phosphorus which were detected in the river water during winter and spring may be partly attributed to the leaching of the applied fertilizers because of nirogen mobilization and soil erosion, following the season's precipitations. The protection of the Evrotas River water Quality must therefore include adequate treatment of the septage produced in the area, as well as the construction of wastewater treatment plants for the major industries of the area. The non-point pollution could be controlled by the restoration of the Evrotas riparian vegetation, together with a more rational use of fertilizers in the area.

Hypomagnesaemic Tetany in Cattle: II. Preventive measures

SUMMARY Methods of prevention are discussed. These aim at increasing the intake of “available magnesium during periods of increased requirements. An essential feature of prevention is that magnesium supplementation is kept up during the whole of the period of risk, although recent work has indicated that a supplement every day may not be necessary as administration of twice the usual amount every other day has given satisfactory protection. Preventive measures include the use of suitable magnesium compounds for direct supplementation by mouth, for topdressing on soils of suitable pH or for applying to the herbage as a dust or as a suspension in water where the soil is more alkaline. On acid soils the use of dolomitic limestone of high magnesium content can provide an effective longterm method of increasing the available soil and pasture magnesium. A more rational use of fertilizers is desirable, particularly the avoidance of large amounts of potassic fertilizers in the spring.