An leasachán P ithreach éifeachtach é sloda próiseála déiríochta?
Tá sé tábhachtach úsáid leasacháin cheimiceacha a laghdú, agus dramhaíl orgánach cosúil le sloda próiseála déiríochta (DPS) a athchúrsáil agus a athúsáid. Cuirfidh sé seo le straitéisí geilleagair chiorclaigh go háirithe do thíortha ina bhfuil diantáirgeadh déiríochta ar nós na hÉireann.
I gCaisleán Bhaile Sheonach Teagasc, rinneamar imscrúdú ar oiriúnacht na dramhaíola déiríochta mar ionadú ar leasachán ceimiceach do thalmhaíocht na hÉireann. Déantar thart ar 0.3x106 go 3x106 L d’eisilteach a tháirgeadh go laethúil ó mhonarchana próiseála bainne laistigh den AE agus is ábhar saibhir cothaitheach é an sloda aisghafa. Áirítear le taighde roimhe seo ar DPS; tréithriú DPS éagsúil, infhaighteacht cothaithigh amhail fosfar (P), nítrigin agus potaisiam ó DPS éagsúla, éifeacht cóireála dramhaíola éagsúla ar infhaighteacht P.
Nuair a goradh ithreacha aigéadacha a raibh P easnamhach orthu le DPS cobhsaithe aol ar feadh sé mhí, mhéadaigh an P a bhí ar fáil san ithir. Mhéadaigh agus d'fheabhsaigh pH na hithreach an tuaslagthacht P i gcomparáid le gnáthleasachán, forfhosfáit thriarach. Ciallaíonn sé seo gur féidir leis an LS-DPS P atá ar fáil go héasca a sholáthar agus gur féidir é a úsáid chun P in ithreacha easnamhacha a mhéadú níos fearr ná TSP; a chabhróidh le feirmeoirí an costas a bhaineann le leasacháin cheimiceacha a cheannach a laghdú.
Chomh maith leis sin, fuaireamar amach go bhfuil freagairt dhifriúil ag uigeachtaí ithreacha éagsúla ar dhramhaíl phróiseála déiríochta, agus ithreacha díoma is freagrúla agus ithreacha dúrabháin gainimh agus cré is lú freagróirí ina dhiaidh sin. Thángamar ar an gconclúid go bhféadfadh an fuíolltáirge seo a bheith ina rogha mhalartach maith ar leasachán fosfair do gach ithir.
Is dairy processing sludge an effective soil P fertiliser?
Dr. Maame Croffie and Dr. Karen Daly
It is important to reduce the use of chemical fertilisers, and recycle and reuse organic waste such as dairy processing sludge (DPS). This will contribute to circular economy strategies especially for countries with intensive dairy production such as Ireland.
In Teagasc Johnstown Castle, we have investigated the suitability of dairy waste as a replacement for chemical fertiliser for Irish agriculture. Approximately 0.3x106 to 3x106 L of effluents are produced daily from milk processing plants within the EU and the recovered sludge is a nutrient-rich material. Previous research on DPS includes; characterization of different DPS, availability of nutrients such as phosphorus (P), nitrogen and potassium from different DPS, effect of different waste treatment on P availability.
When acidic soils that were P deficient were incubated with lime stabilised DPS for six months, available P in soil increased. Soil pH also increased and improved the P solubility compared to conventional fertiliser, triple superphosphate. This means the LS-DPS can provide readily available P and can be used to increase P in deficient soils better than TSP; which will help farmers to cut down on cost in the purchase of chemical fertilisers.
Also, we found that different soil textures have different response to dairy processing waste, with loam soils the most responsive followed by sandy loams and clay soils the least responsive. We concluded that this waste product could be a good alternative to phosphorus fertiliser for all soils.7
