Wagening University point out that Dutch nursery horticulture is extremely efficient . " Looking at food , we are on our way to achieving ' virtually ' zero emissions by 2027 , to match the Water Framework Directive . However , to date , little attention was pay to the other end of the chain : that which go into the greenhouse , i.e. the rootage of these nutrients . "
Unlike open - field arable farming , where animate being manure can be used , glasshouse horticulture depends entirely on inorganic fertilizers : pure minerals that feed the industrial plant when dethaw in water . " Our research take up with phosphorus ( P ) as one of these minerals . One - third of all mineral Lucifer import into the Netherlands is used in nursery gardening . Regardless of our efficiency with these fertilizers , mineral - based fertiliser are mine from finite born reserves . Moreover , minelaying has an environmental impact . "
Residual streams containing phosphorusThis is why research looked into phosphorus from circular informant . They measure several alternative to draw out phosphorus from residual streams using existing technologies , looking at them from the perspective of nursery gardening .
Cow and pig manure and compost moderate comparatively broken levels of phosphorus and already have other uses as well . Compost is also expensive . This rules them out at this point , and there are other sources that seem more viable .
researcher think sewage sludge ash shew lots of potential difference . This is the ash tree that leave from incinerating sewage goo . Large quantities of this ash are grow annually by wastewater treatment flora ( WWTPs ) . Ironically , this ash tree is currently bury deep underground in mines . The sewerage sludge ash tree produced by Dutch WWTPs each year contains 7.5 tonnes of Lucifer , which is three fourth dimension greenhouse horticulture ’s annual demand . Could this be an opportunity to serve conclude the phosphorus loop ?
address grower concerns"Our inquiry shows that , in terms of economics , greenhouse horticulture is an interesting possible marketplace . A distinctive phosphorus fertilizer for greenhouses has a higher price than mineral phosphorus plant food for open - plain farm . Why is morning star from sewerage sludge ash not yet applied in nursery gardening ?
Part of the answer lie in practical hurdle . Some method acting ( like struvite hastiness ) recover phosphorus in a form that makes it unmanageable to apply in greenhouses since the result mathematical product can not be instantly dissolved in water . Instead , an Elvis must be added , which can intend the nutritious recipe will end up modify a second .
Furthermore , high - technical school greenhouse reuse water that is not taken up by the craw . These recirculating systems are what allow greenhouse horticulture to be so nutrient - efficient . If a fertilizer contains contaminant ( heavy metal , for example ) , these contaminants may gather within the arrangement , conduct to jeopardy . The ambition to achieve near - zero nutrient emissions through efficiency makes circularity more challenging . "
They figure the maximal contaminant degree in fertilizer to rule out risks , which should help oneself growers gain self-assurance .
The Living Lab Circular Greenhouse KB project is now in its second year . They have produced an overview of dissimilar P recovery routes to make residuary stream suitable , including technologies already being apply by various company . They also have an overview of the consideration for greenhouse horticulture when using circular daystar .
The remain chance is to link the two sectors . rotary morning star manufacturers are attempt high - value market for their mathematical product but are insufficiently familiar with the greenhouse gardening sector . At the same clip , glasshouse horticulture is evenly unfamiliar with P from residuary streams . Still , the sector is looking for sustainable choice to mineral phosphorus .
Linking producers to growers"To start linking phosphorus retrieval to nursery horticulture , I present at two different scientific league . The audience at the NERM , on nutrient from residual streams , was surprise by the size of it of the Dutch nursery horticulture grocery store and by how well the manipulation of circular P fits this sector . At the EHC , it was the other way orotund . Here , I linked the recovery of minerals to the effective recirculating growing systems used in Dutch greenhouse horticulture .
At both events , I was suffer with ebullience . There are swell opportunities to foster links between these two sectors , which they are continuing in this surviving Lab task . In other projects , they intend to study other fertilizers in a standardised way . These are two populace that are unambiguously capable of help each other and have a lot to gain from becoming more intimate with each other . "
beginning : wur.eu
