effect of phosphorus and organic matter on availability and iron uptake in mays (zea mays l.)

iron is an essential microelement for plant growth. low content of organic matter and excess application of phosphate fertilizer in soils can be affected on availability of iron. in this study the effect of iron, phosphorus and organic matter on growth and iron uptake of mays was evaluated. a greenhouse experiment was conducted with two levels of cattle manure (0 and 1 %), three levels of phosphorus (0, 200, 400 kg.ha-1 triple super phosphate) and three levels of iron (0, 20, 40 kg.ha-1 sequestrene 138). the experiment was carried out based on a completely randomized design with a factorial arrangement using two replications. plants were grown in a sandy loam soil for eight weeks. results showed that application of cattle manure significantly increased shoot dry weight, iron concentration and iron uptake of maize. the application of phosphorus along with iron treatment increased shoot dry weight at 20 kg.ha-1 iron but it had a negative effect at higher levels of iron. application of iron increased concentration and total iron uptake of plants. however, phosphorous revealed an opposite effect. interaction between treatments showed that application of cattle manure can improve the negative effects of excess phosphorus.