BLGG AgroXpertus

Wageningen, Netherlands

BLGG AgroXpertus

Wageningen, Netherlands
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Hanse B.,IRS | Schneider J.H.M.,IRS | Termorshuizen A.J.,BLGG AgroXpertus | Varrelmann M.,Institute of Sugar Beet Research
Crop Protection | Year: 2011

Crop yield has to increase to meet the expanding demand for food, feed and bio-energy, caused by world population growth and increasing wealth. Raising sugar yield is also the key to sustaining the profitability of the sugar beet crop. This paper describes the factors that impacted on yield differences between 26 'top' and 26 'average' growers based on four years yield data (2000-2004). In 2006 and 2007, the top growers had 20% higher sugar yields compared to their neighbouring average growers. Heterodera schachtii and Beet necrotic yellow vein virus (BNYVV) were mainly found on clay soils. Top growers on clay soil had significantly lower infestation levels of H. schachtii (4.4x lower, P = 0.008), BNYVV (2.7x lower, P = 0.016) and other foliar symptoms (Pseudomonas, Phoma betae and Verticillium spp. combined) (1.5x lower, P < 0.001), than the average growers, respectively. On sandy soils, infestation levels of Meloidogyne spp. (P = 0.016), Cercospora beticola (P = 0.005) and Erysiphe betae (P = 0.027) were significantly lower (5x, 1.4x and 1.8x, respectively) for the top growers. The top growers on clay or sand sowed 5 and 6 days earlier respectively, and made more fungicide applications and thus used more fungicides than the average growers. Insect pests were not observed at levels damaging for sugar yield: Insecticidal seed treatments provided sufficient control of insect pests. In multiple regression, 35% of the variance in sugar yield on clay soils was explained by H. schachtii and BNYVV infestation levels and by sowing date. On sandy soils, the infestation levels of Heterodera betae and Aphanomyces cochlioides, number of fungicide applications and sowing date explained 71% of the variance in sugar yield. Despite crop protection measures, the calculated yield losses due to pests and diseases for the top growers were 30.2 and 13.1% and for average growers were 37.1 and 16.7% on sandy and clay soils, respectively. Therefore, pest and disease infestation levels partly explained the differences in sugar yield between top and average growers analysed. The skills and knowledge of the grower are important to reducing damage by pests and diseases. Communication of knowledge, obtained by research, towards growers is vital for the long-term raising of yield and increasing of productivity in sugar beet, as well as in other crops. © 2011 Elsevier Ltd.

Ali M.,Wageningen University | Ali M.,Wageningen UR Livestock Research | Weisbjerg M.R.,University of Aarhus | Cone J.W.,Wageningen University | And 5 more authors.
Animal Feed Science and Technology | Year: 2012

The Dutch feed evaluation system for ruminants uses assumptions and regression equations to estimate the intestinal digestibility of crude protein (CP), neutral detergent fibre (NDF) and starch. These assumptions and equations are based on many different studies, obtained over a very long period. The objective of this study was to develop a unique dataset on the ruminal degradability and the postruminal digestibility of CP, NDF (aNDFom, amylase neutral detergent fibre organic matter basis) and starch in maize and grass silages, using the mobile nylon bag technique. Twenty samples of maize silage and 20 samples of grass silage were used. The samples were selected to represent a broad range in digestibility and chemical composition. Prior to the intestinal incubations, samples were incubated in the rumen for 6. h (starch), 12. h (CP) or 24. h (aNDFom) using the rumen nylon bag technique. Residues from the rumen incubations were transferred to mobile nylon bags and inserted in the duodenum through a cannula. Half of the bags for CP and starch were collected from the ileal cannula and the remaining half of the bags from the faeces. For aNDFom, all the bags were collected from faeces. There was a large variation in the rumen degradability and the intestinal digestibility (small and/or large intestine) of CP, aNDFom and starch. The rumen degradable fractions, the intestinal digestible fractions and the total tract undigested fractions of CP, aNDFom and starch were influenced by their proportions in the maize and grass silages. The results proved the assumption of the Dutch feed evaluation system that the rumen undegraded starch is completely digested in the small intestine of dairy cows. Regression showed that the rumen degradability, the intestinal digestibility and the total tract undigested contents were influenced by the chemical composition of the maize and grass silages. © 2012 Elsevier B.V.

PubMed | Wageningen University, BLGG AgroXpertus, Wageningen UR Livestock Research and Product Board Animal Feed
Type: Journal Article | Journal: Journal of animal physiology and animal nutrition | Year: 2016

In insitu nylon bag technique, many feed evaluation systems use a washing machine method (WMM) to determine the washout (W) fraction and to wash the rumen incubated nylon bags. As this method has some disadvantages, an alternate modified method (MM) was recently introduced. The aim of this study was to determine and compare the W and non-washout (D+U) fractions of nitrogen (N) and/or starch of maize and grass silages, using the WMM and the MM. Ninety-nine maize silage and 99 grass silage samples were selected with a broad range in chemical composition. The results showed a large range in the W, soluble (S) and D+U fractions of N of maize and grass silages and the W, insoluble washout (W-S) and D+U fractions of starch of maize silages, determined by both methods, due to variation in their chemical composition. The values for N fractions of maize and grass silages obtained with both methods were found different (p<0.001). Large differences (p<0.001) were found in the D+U fraction of starch of maize silages which might be due to different methodological approaches, such as different rinsing procedures (washing vs. shaking), duration of rinsing (40min vs. 60min) and different solvents (water vs. buffer solution). The large differences (p<0.001) in the W-S and D+U fractions of starch determined with both methods can led to different predicted values for the effective rumen starch degradability. In conclusion, the MM with one recommended shaking procedure, performed under identical and controlled experimental conditions, can give more reliable results compared to the WMM, using different washing programs and procedures.

Thoden T.C.,Wageningen University | Korthals G.W.,Wageningen University | Termorshuizen A.J.,BLGG AgroXpertus
Nematology | Year: 2011

The use of organic soil amendments, such as green manures, animal manures, composts or slurries, certainly has many advantageous aspects for soil quality and is suggested as a promising tool for the management of plant-parasitic nematodes. However, during a recent literature survey we also found numerous studies reporting an increase of plant-parasitic nematodes after the use of organic amendments. Therefore, we critically re-evaluated the usefulness of organic amendments for nematode management and suggest possible mechanisms for a stimulation of plant-parasitic nematodes, as well as mechanisms that might be causing a reduction of plant-parasitic nematodes. In addition, we also elucidate a possible mechanism that might be responsible for the observed overall positive effects of organic amendments on crop yields. It is likely that a significant part of this is, inter alia, due to the proliferation of non-pathogenic, free-living nematodes and their overall positive effects on soil microbial populations, organic matter decomposition, nutrient availability, plant morphology and ecosystem stability. © 2011 BRILL.

Van Den Elsen S.,Wageningen University | Ave M.,Wageningen University | Schoenmakers N.,BLGG AgroXpertus | Landeweert R.,BLGG AgroXpertus | And 2 more authors.
Phytopathology | Year: 2012

Potato cyst nematodes (PCNs) are quarantine organisms, and they belong to the economically most relevant pathogens of potato worldwide. Methodologies to assess the viability of their cysts, which can contain 200 to 500 eggs protected by the hardened cuticle of a dead female, are either time and labor intensive or lack robustness. We present a robust and cost-efficient viability assay based on loss of membrane integrity upon death. This assay uses trehalose, a disaccharide present at a high concentration in the perivitelline fluid of PCN eggs, as a viability marker. Although this assay can detect a single viable egg, the limit of detection for regular field samples was higher, ≈10 viable eggs, due to background signals produced by other soil components. On the basis of 30 nonviable PCN samples from The Netherlands, a threshold level was defined (ΔAtrehalose = 0.0094) below which the presence of >10 viable eggs is highly unlikely (true for ≈99.7% of the observations). This assay can easily be combined with a subsequent DNA-based species determination. The presence of trehalose is a general phenomenon among cyst nematodes; therefore, this method can probably be used for (for example) soybean, sugar beet, and cereal cyst nematodes as well. © 2012 The American Phytopathological Society.

Rybarczyk-Mydlowska K.,Wageningen University | Mooyman P.,Wageningen University | Van Megen H.,Wageningen University | Van Den Elsen S.,Wageningen University | And 7 more authors.
Phytopathology | Year: 2012

Foliar nematodes, plant-parasitic representatives of the genus Aphelenchoides, constitute a minority in a group dominated by fungivorous species. Distinction between (mostly harmless) fungal feeding Aphelenchoides species and high impact plant parasites such as A. besseyi, A. fragariae, A. ritzemabosi, and A. subtenuis is severely hampered by the scarcity of informative morphological characters, some of which are only observable in specific developmental stages. Poor description of a number of non-plant-parasitic Aphelenchoides species further complicates identification. Based on (nearly) full-length small subunit ribosomal DNA (SSU rDNA) sequences (?1,700 bp), a phylogenetic tree was generated, and the four target species appeared as distinct, well-supported groups. Notably, this genus does not constitute a monophyletic group: A. besseyi and A. ritzemabosi cluster together and they are phylogenetically isolated from A. fragariae, A. subtenuis, and most other fungivorous species. A phylum-wide SSU rDNA framework was used to identify species-specific DNA motifs. For the molecular detection of four plant-parasitic Aphelenchoides species, polymerase chain reaction primers were developed with high, identical annealing temperatures (63°C). Within the molecular framework presented here, these primers can be used for the rapid screening of plant material and soil for the presence of one or multiple foliar nematode species. © 2012 The American Phytopathological Society.

Reijneveld A.,BLGG AgroXpertus | Oenema O.,Wageningen University
Nutrient Cycling in Agroecosystems | Year: 2012

Compliance with current phosphorus (P) fertilization recommendations would ultimately result in a soil P status of agricultural land in the agronomical optimal range. In practice though there are large variations in soil P status among farms and fields. Our study aimed at increasing the understanding of the cause-effect relationships for these spatial variations in soil P test values. The Northeast Polder in The Netherlands was chosen as study area, because of its characteristics. It was reclaimed from the sea in 1942, has one major soil type (calcareous loam), well-educated farmers, one dominant land use (arable farming) and little pressure to use animal manure. We tested the hypothesis that in this polder mean P status has developed towards the optimal range with a small standard deviation. We analysed available soil P analyses records (>30,000) from the period ~1950-2004, and conducted a questionnaire about fertilization practices among farmers. The soil P(w) values increased steadily and significantly from the agronomical range 'low' to 'ample sufficient' from 1971 to 2004. Variation within and between farms also increased. About 45 % of the farmers appear to aim at a soil P status above the agronomical optimal range, and <70 % of the farmers indicated that they are uncertain whether the obtained increase in soil P(w) status is actually plant available P. In conclusion, our hypothesis was rejected: for farmers in our study area, risk avoidance seems the decisive factor for pursuing a soil P status above the agronomical optimal range. If even well-educated farmers question the official fertilizer recommendations and aim at higher levels of soil P fertility, also other farmers worldwide may continue to aim such supra-optimal soil P status. This is undesirable given the diminishing P resources. Possible solutions could be to define more refined P fertilization recommendations and better and more intensified communication of those recommendations to farmers and their advisers. © 2012 Springer Science+Business Media B.V.

Reijneveld J.A.,BLGG AgroXpertus | Ehlert P.A.I.,Wageningen University | Termorshuizen A.J.,BLGG AgroXpertus | Oenema O.,Wageningen University
Soil Use and Management | Year: 2010

The Netherlands has a high cumulative mean phosphorus (P) balance. In the 20th century, cumulative mean P surpluses were ca. 4500-kg P2O5/ha. The annual surpluses have levelled off because of manure application limits from 1984 onwards. We report the effect of soil type, land use, and manure policy on changes in soil P of fields in the Netherlands during the 20th century. We used data (>5 million soil P tests) from the soil analysis laboratory BLGG AgroXpertus. Our results show that soil P has increased on average to fairly high and high ratings. Differences between regions and between land use have remained high from the first records in the 1930s; on arable land the increase continued until the end of our study period while on grassland no changes are evident in the last decades. In general regions with high livestock density have high soil P status. Soil P increased in the order bulbfields-< grassland-< arable land-<-maize land-<-horticulture, and in the order loess-<-clay-<-peat-<-sand soils. Spatial variations in P values reflect more the market value of the crops and regional availability of animal manure than (fertilizer) recommendations. Manure policy since 1984 has resulted in increasingly tight restrictions on P application from manure and fertilizers, but the effects are not yet clearly reflected in changed trends in soil P. © 2010 The Authors. Journal compilation © 2010 British Society of Soil Science.

Reijneveld A.,BLGG AgroXpertus | Termorshuizen A.,BLGG Research | Vedder H.,BLGG Research | Oenema O.,Wageningen University
Communications in Soil Science and Plant Analysis | Year: 2014

Soil phosphorus (P) tests are used for P fertilization recommendations, environmental evaluations, and occasionally for legislation purposes. The basis of fertilization recommendation as function of soil P status was established in the 1950s-1960s. Since then the agroeconomic environment has altered: Environmental protection became increasingly important and P rock resources for fertilizers appeared exhaustible. Also, new insights in soil testing and fertilization recommendations reflecting more efficient use of P became available. However, these new insights seem hard to implement into agricultural practice, to a large extent because replacing existing soil tests and recommendations would imply a very significant effort with respect to introducing new tests and recommendations by fertilization trials in practice. The same would apply for environmental evaluations. Here, a novel, three-step schedule for introducing new soil tests is proposed: (1) establishing new promising soil tests, (2) creating regression models between the old and new soil tests, and (3) implementing the new soil test stepwise by fertilization trials. In this way, the knowledge based on the old soil tests can be used until the new soil tests and their subsequent crop responses are validated sufficiently. As a novel P test we considered combining soil P intensity [as reflected by P-calcium chloride (CaCl2)] with P capacity [as reflected by P-ammonium lactate (Al)] and P-buffering capacity (as reflected by P-Al/P-CaCl2 ratio) characteristics. Researchers tested whether this novel soil test can predict P water (Pw), P-calcium lactate / acetate (CAL), and P-Olsen values. To test the hypothesis, four datasets were used (two with Pw, one with P-CAL, and one with P-Olsen). In all datasets additional soil characteristics were available including soil type. Regression models with Radj 2 from 0.80 to 0.93 were obtained by using P-Al, P-CaCl2, and soil type. It can be concluded that these regressions can be used as a helpful intermediate instrument when introducing fertilization recommendations based on new soil tests. Predicting one soil P test out of other soil characteristics, analogous to the predicted Pw, P-CAL, and P-Olsen, could also be helpful in comparing P statuses of agricultural land in different nations. © 2014 Taylor and Francis Group, LLC.

Reijneveld J.A.,BLGG AgroXpertus | Abbink G.W.,BLGG AgroXpertus | Termorshuizen A.J.,BLGG Research | Oenema O.,Wageningen University
European Journal of Agronomy | Year: 2014

It is reasonable to expect that compliance with grassland fertilization recommendations in the long run results in optimal soil fertility, and subsequent herbage quality. Here, we evaluate the development of soil, herbage and manure characteristics and their relation over the last decades. We hypothesized that herbage and manure quality are related with soil fertility. We used a large database with results of soil tests, spring forage quality characteristics, and manure analyses, which were made on demand of dairy farmers. We considered the Netherlands as a whole and three selected regions with contrasting soil types (sandy soil, riverine clay, and peaty marine clay). Effects of soil fertility on herbage quality were evident when comparing farms. Farms higher in soil P and K generally have correspondingly higher contents in forage. On average, soil fertility and herbage characteristics were within or just above the agronomical optimal range during the last decades. Herbage crude protein content decreased in all regions during last two decades, which is likely an effect of legislative measures on decreasing the application of N. Selenium (Se) and sulphur (S) contents increased sharply on sandy soils, likely because of increased use of Se and S containing fertilizers. Manure composition did not differ between soil types. In conclusion, at farm level, the element composition of herbage reflected the soil fertility status. The contents of S, P, K, Na, Mg, and Ca in the herbage were all significantly influenced by soil fertility characteristics. Our results emphasize the importance of maintaining soil fertility for high quality roughage production. © 2014 Elsevier B.V.

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