▁natural ▁rate ▁and ▁far ▁exceed ▁replacement ▁by ▁soil ▁production . ▁The ▁till age ▁of ▁agricult ural ▁lands , ▁which ▁breaks ▁up ▁soil ▁into ▁fin er ▁particles , ▁is ▁one ▁of ▁the ▁primary ▁factors . ▁The ▁problem ▁has ▁been ▁ex ac erb ated ▁in ▁modern ▁times , ▁due ▁to ▁mechan ized ▁agricult ural ▁equipment ▁that ▁allows ▁for ▁deep ▁p low ing , ▁which ▁sever ely ▁increases ▁the ▁amount ▁of ▁soil ▁that ▁is ▁available ▁for ▁transport ▁by ▁water ▁er os ion . ▁O thers ▁include ▁mon o - cro pping , ▁far ming ▁on ▁ste ep ▁s lop es , ▁p estic ide ▁and ▁chemical ▁fert il izer ▁usage ▁( which ▁kill ▁organ isms ▁that ▁bind ▁soil ▁together ), ▁row - cro pping , ▁and ▁the ▁use ▁of ▁surface ▁ir rig ation . ▁A ▁complex ▁overall ▁situation ▁with ▁respect ▁to ▁defining ▁nut ri ent ▁losses ▁from ▁so ils , ▁could ▁arise ▁as ▁a ▁result ▁of ▁the ▁size ▁select ive ▁nature ▁of ▁soil ▁er os ion ▁events . ▁L oss ▁of ▁total ▁ph osph orus , ▁for ▁instance , ▁in ▁the ▁fin er ▁er oded ▁fraction ▁is ▁greater ▁relative ▁to ▁the ▁whole ▁soil . ▁Ext rap ol ating ▁this ▁evidence ▁to ▁predict ▁subsequent ▁behaviour ▁within ▁receiving ▁aqu atic ▁systems , ▁the ▁reason ▁is ▁that ▁this ▁more ▁easily ▁transport ed ▁material ▁may ▁support ▁a ▁lower ▁solution ▁P ▁concentration ▁compared ▁to ▁co ar ser ▁s ized ▁fra ctions . ▁Till age ▁also ▁increases ▁wind ▁er os ion ▁rates , ▁by ▁de h yd rating ▁the ▁soil ▁and ▁breaking