Effects Of HA-K Fertilizers On The Absorption And Utilization Of Potassium In Sweet Potato

This experiment was carried out at the experimental station of Shandong Agricultural University from May 2008 to October 2009. The different factors of HA-K fertilizer on the absorption and utilization of potassium in sweet potato have been done a systematic study. The main results were as follows:1 Effect of HA-K fertilizer on the absorption and utilization of potassium in sweet potatoHA-K fertilizer treatment increased the potassium accumulation of sweet potato and increased the absorption and utilization of potassium at last. Comparing with mixed HA and K fertilizer treatment and H₂SO₄ treatment, the recovery efficiency of potassium fertilizers of HA-K fertilizer treatment were increased 16.39%, 20.12%; the efficiency of potassium fertilizers were increased 20.68%, 39.84%.2 Effect of HA-K fertilizer on the slow release of potassium fertilizerComparing with H₂SO₄, the potassium release peak of HA-K fertilizer was reduced. The potassium release rate of HA-K was lower than that of H₂SO₄ in the early, but it is higher in the late. The potassium accumulation release rate curve was smoother than that of H₂SO₄, have a good effect on the slow release of potassium release results. 3Effect of HA-K fertilizer on stimulate the growth of sweet potatoHA-K fertilizer treatments promote the growth of sweet potato, improve the biomass yield of sweet potato. Potassium or HA could increased the fresh yield and dry matter. Potassium fertilizer promoted the transfer of shoot dry matter and increased distribution proportion of dry matter in subterranean part, and the HA-K fertilizer treatment had the best effect on that.Comparing with H₂SO₄ treatment and mixed HA and K treatment, the HA-K fertilizer treatment was increased chlorophyll content. Potassium fertilizer treatments and HA fertilizer treatments improved photosynthesis, and the HA-K fertilizer treatment had the best effect on that. Potassium fertilizer treatments and HA fertilizer treatments increased superoxide dismutase (SOD), peroxidase (POD) activity, decreased malondiadehyde (MDA) content. Comparing with mixed HA and K fertilizer treatment, HA-K fertilizer treatment increased soluble protein content in early and medium time, and SOD, POD activity in the late.The fertilization treatments increased root activity early enlargement of sweet potato storage roots. Comparing with other fertilization treatments, HA-K fertilizer treatment could more effective to improve the root activity, and improve absorbing root more differentiated storage root.Comparing with H₂SO₄ treatment and mixed HA and K fertilizer treatment, HA-K fertilizer treatment increased N/K ratio of sweet potato at early time, and decreased it at the last.4 Effect of HA-K fertilizer on different forms of potassium of soilRapidly available potassium content in soil of HA-K fertilizer treatment was lower than mixed HA and K treatment at early time, but it is higher at last. Comparing with non-fertilizer, HA fertilizer treatment decreased rapidly available potassium content soil, comparing with H₂SO₄ treatment, mixed HA and K treatment and HA-K fertilizer treatment had the same case.During growth of sweet potato, the available potassium content in soil of HA fertilizer treatments had a marked increasing trend, and HA-K fertilizer treatment most marked, but that of H₂SO₄ treatment had no marked change. Comparing with non-fertilizer treatment, slowly available potassium in soil of HA fertilizer treatments were decreased, but that of H₂SO₄ treatment was increased.