Differences in cover crop contributions to phosphorus uptake by ryegrass in two soils with low and moderate P status

Growing evidence has emerged that cover crops may be able to improve phosphorus (P) cycling and contribute the P nutrition of subsequent crop. This could particularly important in farming systems, with limited access inputs where low soil availability been identified. In a pot experiment using soils labelled radioactive 33P, we examined how range crop residues directly uptake ryegrass, as well they affect ryegrass from pool. Two moderate status (6.3 15.3 mg Olsen-P kg−1 soil) were chosen for models are gradually becoming depleted available P. Residues five species (buckwheat (Fagopyrum esculentum Moench), oilseed radish (Raphanus sativus L.), garden sorrel (Rumex acetosa white lupine (Lupinus albus L.) hairy vetch (Vicia villosa Roth)) showed wide species-dependent variability concentration (3.4–8.8 g-1 DM) other quality traits. Cover contributed less growth than water-soluble fertilizer. At same application dose, 0.4–2.3 (18–42 %) total depending on status, whereas mineral fertilizer up 5.2 (46 %). soil, significantly increased compared control without (by 93 75 %, respectively), 61 43 respectively). The effects correlated but only moderately their concentration, content water-extractable C:P ratio (R2 = 0.4, R2 0.4 0.5, As expected, contribution was lower higher sorption capacity these two species-dependent. Addition resulted greater buckwheat lupin highest ratios gave rise substantially smaller P, which is an indication microbial immobilization. Our study demonstrated crop, some cases substantially, status.