The Effect Of Several Fertilization Practices On Restoration Of The Degraded Gleyed Paddy Soils

Rice production and sustainable development for agriculture in China waslimited by poor quality of gleyed paddy soils, such as the accumulation of reductivesubstance, low availability of soil nutrients and declined soil productivity, due to poordrainage. In the past, researches focused more on engineering technology to improvegleyed paddy soils. However, information on agricultural practice to improve this kindof soils is rather scanty. In the present study, field experiments were conducted tostudy on effects of fertilization practices on the physico-chemical properties and thecrop productivity in gleyed paddy soils from the slate in Taojiang county and theQuaternary Red Clay in Ningxiang county, respectively.1. The fertilization practices exhibited distinct influences on crop productivity insoils developed from different parent materials. In the gleyed paddy soils developedfrom slate, application of NPK+organic fertilizer showed the highest rice yield,followed by NPK+CaO₂ and specific fertilizer for rice and NPK+Si. As comparedwith the control, early rice yield increased by 15.3ï¼…,10.2ï¼…,10.5ï¼…and 2.4ï¼…byapplication of NPK+ organic fertilizer, NPK+CaO₂, specific fertilizer for rice andNPK+Si, respectively. Correspondingly, late rice yield increased by 14.6ï¼…,9.0ï¼…,6.2ï¼…and 3.9ï¼…for above fertilizer treatments, respectively. The effective spikes,1000-grain weight, and seeds per spike were improved by fertilizer applications,which resulted in increasing rice yield. However, the influences of fertilizerapplication on rice yield in the gleyed paddy soils developed from Quaternary RedClay was minor. 2. Fertilization practice showed inconsistent influences on improving soil redoxstatus in soils developed from different parent materials. In the gleyed paddy soilsdeveloped from Quaternary Red Clay, there were no significant difference of theamount of total reductive substances and active reductive substances among fivetreatments in the present experiment. This maybe was due to high soil organic matterin the selected soil. However, in the gleyed paddy soils developed from slate, both thetotal reductive substances and active reductive substances in NPK+ organic fertilizertreatment were higher than that in other fertilizer treatments. All fertilizer treatmentsexhibited lower Fe²⁺ concentration as compared with control treatment. Moreover,application of specific fertilizer for rice was more effective to decrease Fe²⁺concentration, followed by NPK+CaO₂, NPK+ organic fertilizer and NPK+Si.3. The content of available nutrients in gleyed paddy soils was influenced byfertilizations. The application of NPK+ organic fertilizer increased soil available Nand P content and NPK+Si increased soil available K content at all growth stage forearly rice. Furthermore, all fertilizer treatments increased soil available P content atthe middle and late growth stage and available K content at all stages for late rice.