Effect Of Different Compositions Of Cake Fertilizer And Nitrogen Forms On Flue-Cured Tobacco Growth And Rhizosphere Soil Biological Activity

That the quality of flue-cured tobacco can be improved when fertilized with rotted cake fertilizer is indicated in many studies, but the real mechanisms are known little. Except for the role of its nutrition constituents as organic fertilizer, the effect on soil environment can't be disregardful. Therefore, two types of typical soil (Yellow Cinnamon Soil and Fluvo-aquic Soil) elected in Henan province, K326 as test flue-cured variety, a pot experiment adopted, we studied the dynamic changes of microbe number and enzyme activity in tobacco rhizosphere soil and tobacco dry matter under different compositions of sesame seed cake fertilizer and nitrogen forms from 2001 to 2002.The main results were as followings.1.A close relationship existed in between rhizosphere soil biological activity and tobacco plant growth. Most of microbe number except the change of bacteria and fungi in yellow cinnamon soil and enzyme activity had peaks during 28-53d after transplant when tobacco plant and root were in vigorous growth stage. The actions of many microbes could build up soil activity that contributed to root absorption and utilization for nutrition; Furthermore, the quick growth of tobacco plant could stimulate microbe growth and increase. Therefore, the transaction between tobacco plant and soil biological activity was realized by affecting the rhizosphere environment.2.They were found that different quantity of rotted cake fertilizer had different behalf in the same soil and the same one hadn't the same effect in two soils. In fluvo-aquic soil, when NO3":NH4+=1 :l,the treatment mixing with 40% rotted cake fertilizerC T4 )was best to all test indexes. Comparing with chemical treatment (Tj) ,different quantity of rotted cake fertilizer could raise phosphatase, invertase and celluse activity, multiplicate the number of bacteria, fungi, actinomyces and ammonificators, speed up tobacco plant and root growth in vigorous growth stage, and increase dry matter accumulation except lower protease and urease activity(except mixing with 60% rotted cake fertilizer (Te)).In yellow cinnamon soil, different quantity of rotted cake fertilizer could strengthen the rhizospheresoil biological activity to some extent except urease comparing with chemical treatment. When NO3-~:NH4M=1: 1, 20% rotted cake fertilizer(T2) mixed had the biggest amplitude on rhizosphere soil enzyme activity, while the ratio of 40% was the best contribution to the multiplication of rhizosphere microbe, tobacco plant accumulation and dry root weight, which was unlike that in fluvo-aquic soil.3.From the results of mixing with the equal rotted and fresh sesame seed cake fertilizer, we found that:In fluvo-aquic soil, 20% fresh cake fertilizer mixed (T7) compared to the equal rotted cake fertilizer (12) , only protease and celluse activity were lower, and bacteria and fungi were less. Compared with mixing equal rotted cake fertilizer (T5) ,40% fresh cake fertilizer mixed (Tg) had only lower celluse activity and less ammonificators. In yellow cinnamon soil, 20% fresh cake fertilizer mixed (T7) compared to the equal rotted cake fertilizer mixed (T2) , it had higher phosphatase and celluse activity and more actinomyces, ammonificators and cellulose-decomposing bacteria. Compared with mixing equal rotted cake fertilizer(T5), 40% fresh cake fertilizer mixed (T8) enhanced protease, phosphatase and celluse activity, and augmented ammonificators and cellulose-decomposing bacteria. There was one same law in two soils regarding tobacco growth and dry matter accumulation, that was to say,20% fresh cake fertilizer mixed (T?) was better than the equal rotted cake fertilizer mixed (T2) ; When 40% fresh cake fertilizer mixed (T8), it was not better than the equal rotted cake fertilizer mixed (T5) . Hence, when 20% fresh cake fertilizer mixed (T7) , soil biological activity and tobacco plant growth were better than these in the treatment of mixing the equal rotted cake fertilizer (T5) ; Though, when the ratio of cake fertilizer came to 40%,it had higher soil biological activity an...