( ( ( The pH ) ( of ( the soil ) ) ) ( ( is ( critical ( to ( ( iron availability ) ( since ( ( under ( alkaline conditions ) ) ( iron ( ( combines readily ) ( with ( phosphates ( , ( carbonates ( and ( hydroxyl ions ) ) ) ) ) ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NP (DT The) (NN pH)) (PP (IN of) (NP (DT the) (NN soil)))) (VP (VBZ is) (ADJP (JJ critical) (S (VP (TO to) (VP (VB iron) (NP (NN availability)) (SBAR (IN since) (S (PP (IN under) (NP (JJ alkaline) (NNS conditions))) (NP (NN iron)) (VP (VBZ combines) (ADVP (RB readily)) (PP (IN with) (NP (NNS phosphates) (, ,) (NNS carbonates) (CC and) (NN hydroxyl) (NNS ions))))))))))) (. .)))
The pH of the soil is critical to iron availability since under alkaline conditions iron combines readily with phosphates, carbonates and hydroxyl ions.
(ROOT (S (NP (NNP Iron) (NNS ions)) (VP (VBP are) (ADJP (JJ critical) (PP (IN for) (NP (NP (DT the) (NN formation)) (PP (IN of) (NP (NN hemoglobin))))))) (. .)))