Rapportage bemesting 2007 : deelrapport sector bloembollen : telen met toekomst

Voor u ligt de rapportage bemesting van het praktijknetwerk Telen met toekomst voor de open teelten voor het jaar 2007. Het is het laatste jaarverslag van dit vierjarige onderzoeksproject. In 2008 wordt Telen met toekomst op een andere wijze voortgezet. Dit rapport geeft het resultaat van de analyse van de bemesting van het vierde jaar van de kernbedrijven in Telen met toekomst, waarbij de resultaten getoetst worden tegen de gebruiksnormen 2008. Tevens wordt een beoordeling gegeven van ontwikkelingen in de toepassing van de Best Practices Bemestin

Leaf CO2 assimilation and leaf dynamics in catch crops during autumn and winter at two levels of nitrogen supply

This study relates the leaf CO2 assimilation and leaf dynamics of nitrogen catch crops to environmental conditions. Winter rye (Secale cereale) and fodder radish (Raphanus sativus) were grown as catch crops in an outdoor pot experiment at two rates of nitrogen supply (N2 higher than N1) in Wageningen, Netherlands, from August 1993 until April 1994. Biomass increased with increasing N supply. There was no net growth after mid-November. The number of tillers in rye and of appeared leaves in radish were higher in N2 than in N1. Leaf appearance rate increased with temperature in fodder radish and rye. Tillering in rye ceased in mid-October. Leaf lifespan was related to the temperature sum between leaf emergence and leaf death. Leaf lifespan was 478 +or- 68 degrees C day in fodder radish. In rye, the leaf lifespan gradually decreased from 592 +or- 66 to 389 +or- 25 degrees C day and from 545 (1 observation) to 401 +or- 64 degrees C day in N1 and N2, respectively. In young leaves, Amax (light-saturated CO2 assimilation rate) was approximately 1.2 mg CO2 m-2 leaf s-1 in September and 0.5 mg CO2 m-2 leaf s-1 later on, independent of species and N supply, N supply affected the organic N concentrations only in the older leaves. Amax was not dependent on temperature at measurement (range: 12-19 degrees C in September, 5-15 degrees C from November until March), but, in contrast, strongly related to temperature and irradiance during the preceding growth period. Leaf nitrate concentrations increased with N supply. Water-soluble carbohydrate concentrations were higher in N1 than in N2 and higher in rye than in fodder radish. They fluctuated during the season. It is concluded that overall growth rates were limited by process rates other than that of leaf CO2 assimilation per unit leaf area in both N1 and N2

Root, soil water and nitrogen dynamics in a catch crop - soil system in the Wageningen Rhizolab

Catch crops (winter rye [Secale cereale] and fodder radish [Raphanus sativus]) were grown on lysimeters with rhizotron facilities in Wageningen, Netherlands, from September-March (1993-94) and August-March (1994-95) in order to study root growth and water and nitrogen dynamics under different regimes of irrigation and N supply. Catch crops took up 20-30 g N/msuperscript 2, of which 37-48% was present in dead leaves in March. Rooting depth increased by 2.6 cm/day for both species at the start of the growing season. Catch cropping reduced the NO-3-N concentration in the soil considerably, initially in the top layers and then further down the soil profile. The reduction in total leached N was similar to the total crop N uptake. Nitrate-N concentrations in leached water were reduced by 49-85 mg/litre (62-99%), depending upon N availability and irrigation. Due to catch cropping the NO-3-N concentration in the percolate decreased with increasing irrigation (or precipitation), whereas the amount of N leached increased with irrigation. Evapotranspiration from a catch cropped soil was close to the potential evapotranspiration under optimal growth conditions

Hardware/Software Co-design Applied to Reed-Solomon Decoding for the DMB Standard

This paper addresses the implementation of Reed- Solomon decoding for battery-powered wireless devices. The scope of this paper is constrained by the Digital Media Broadcasting (DMB). The most critical element of the Reed-Solomon algorithm is implemented on two different reconfigurable hardware architectures: an FPGA and a coarse-grained architecture: the Montium, The remaining parts are executed on an ARM processor. The results of this research show that a co-design of the ARM together with an FPGA or a Montium leads to a substantial decrease in energy consumption. The energy consumption of syndrome calculation of the Reed- Solomon decoding algorithm is estimated for an FPGA and a Montium by means of simulations. The Montium proves to be more efficient

Root, soil water and nitrogen dynamics in a catch crop-soil system in the Wageningen Rhizolab.

Catch crops (winter rye [Secale cereale] and fodder radish [Raphanus sativus]) were grown on lysimeters with rhizotron facilities in Wageningen, Netherlands, from September-March (1993-94) and August-March (1994-95) in order to study root growth and water and nitrogen dynamics under different regimes of irrigation and N supply. Catch crops took up 20-30 g N/msuperscript 2, of which 37-48% was present in dead leaves in March. Rooting depth increased by 2.6 cm/day for both species at the start of the growing season. Catch cropping reduced the NO-3-N concentration in the soil considerably, initially in the top layers and then further down the soil profile. The reduction in total leached N was similar to the total crop N uptake. Nitrate-N concentrations in leached water were reduced by 49-85 mg/litre (62-99%), depending upon N availability and irrigation. Due to catch cropping the NO-3-N concentration in the percolate decreased with increasing irrigation (or precipitation), whereas the amount of N leached increased with irrigation. Evapotranspiration from a catch cropped soil was close to the potential evapotranspiration under optimal growth conditions

Leaf CO2 assimilation and leaf dynamics in catch crops during autumn and winter at two levels of nitrogen supply.

This study relates the leaf CO2 assimilation and leaf dynamics of nitrogen catch crops to environmental conditions. Winter rye (Secale cereale) and fodder radish (Raphanus sativus) were grown as catch crops in an outdoor pot experiment at two rates of nitrogen supply (N2 higher than N1) in Wageningen, Netherlands, from August 1993 until April 1994. Biomass increased with increasing N supply. There was no net growth after mid-November. The number of tillers in rye and of appeared leaves in radish were higher in N2 than in N1. Leaf appearance rate increased with temperature in fodder radish and rye. Tillering in rye ceased in mid-October. Leaf lifespan was related to the temperature sum between leaf emergence and leaf death. Leaf lifespan was 478 or- 68 degrees C day in fodder radish. In rye, the leaf lifespan gradually decreased from 592 or- 66 to 389 or- 25 degrees C day and from 545 (1 observation) to 401 or- 64 degrees C day in N1 and N2, respectively. In young leaves, Amax (light-saturated CO2 assimilation rate) was approximately 1.2 mg CO2 m-2 leaf s-1 in September and 0.5 mg CO2 m-2 leaf s-1 later on, independent of species and N supply, N supply affected the organic N concentrations only in the older leaves. Amax was not dependent on temperature at measurement (range: 12-19 degrees C in September, 5-15 degrees C from November until March), but, in contrast, strongly related to temperature and irradiance during the preceding growth period. Leaf nitrate concentrations increased with N supply. Water-soluble carbohydrate concentrations were higher in N1 than in N2 and higher in rye than in fodder radish. They fluctuated during the season. It is concluded that overall growth rates were limited by process rates other than that of leaf CO2 assimilation per unit leaf area in both N1 and N2

3D Face reconstruction from moving camera with stationary lighting conditions

This paper describes the development of a 3D face reconstruction algorithm which is able to reconstruct the depth map of a face from a handheld moving camera, where the face remains stationary in space and the lighting conditions remain constant. Camera calibration is used to undistorted the movie frames and local template matching is applied by matching keypoints between consecutive frames. The described algorithm sets the first steps in the development of a tool which can output a 3D printed facial mask for clinical use

De fosfaatbehoefte van vaste planten op duinzandgrond

De huidige fosfaataanvoernorm is 85 kg/ha. In het Vierde Nederlands Actieprogramma betreffende de Nitraatrichtlijn wordt voorgesteld deze norm geleidelijk te verlagen naar 50 tot 75 kg P2O5 per ha, afhankelijk van de fosfaattoestand in de grond. Uit eerder onderzoek blijkt dat de fosfaatafvoer van vaste planten (m.n. Astilbe) hoger kan zijn dan deze aanvoernormen. In deze studie wordt verkend of, en zo ja hoe, vaste planten optimaal bemest kunnen worden binnen de aangescherpte aanvoernormen. Ook bij efficiëntere bemesting binnen de normen zal de fosfaatnorm in het oppervlaktewater overschreden worden in uitspoelend bodemwater. Een alternatieve oplossing is de zuivering van drainagewater met behulp van fosfaatfilters. deze oplossing past (nog) niet binnen de huidige regelgeving

Parameters of the attenuated schistosome vaccine evaluated in the olive baboon

Five exposures of baboons to the attenuated schistosome vaccine gave greater protection than three exposures, but this attenuation was not sustained when challenge was delayed. Within the scope of the data collected, fecal egg counts and circulating antigen levels did not accurately predict the observed worm burdens. Levels of immunoglobulin G at challenge correlated best with protection, but there was little evidence of a recall response

Uit de mest- en mineralenprogramma's : Efficiënte stikstofbemesting bij tulp

In het project 'Ontwikkeling van geleide bemestingssystemen' in de Mest en Mineralenprogramma's wordt onderzoek uitgevoerd om een optimale productie te realiseren met zo min mogelijk stikstofaanvoer en -verlies. Daarvoor wordt gestreefd naar lage bodemvoorraden van stikstof, zodat er weinig verloren kan gaan, en naar een hoge efficiëntie van toegediende meststoffen. Het onderzoek van PPO en PRI richt zich op het verbeteren van bestaande bemestingssystemen, ontwikkelen van nieuwe systemen en toetsen van systemen in praktijksituatie