Effect of Water and Nitrogen Coupling Using on Soil Physical and Chemical Properties in Tobacco Areas and the Yield and Quality of Fule-cured Tobacco in Yibin
|School||Henan Agricultural University|
|Keywords||flue-cured tobacco water and nitrogen coupling water-fertilizer utilization ratio plant development|
Field experiments were carried out with Yunyan 85 to investigate the effects of water-nitrogen interaction on the quality of tobacco , water-fertilizer utilization ratio and physics and chemistry characters of soil planting tobacco.The purpose of the experiments were to find out the appropriate water-nitrogen system , on which the increase of water-fertilizer utilization ratio and the mutual regulation between water and fertilizer depend under different micro-irrigation systems in the year of 2009-2010.The results were showed as follows:1 The effects of water and nitrogen coupling on the soil physical indicatorsThe experiment showed that the soil bulk density decreased with the increasing of nitrogen and increased with the increasing of water;meanwhile,the soil bulk density range became smaller with the increasing of soil depth.Without irrigation ,soil relative water content in the0~40cm depth increased with the increase of nitrogen under application rate range from 0 to 108.4 kg/hm2 ,but it decreased when the nitrogen application was above 108.4 kg/hm2.In the 40~80cm depth, the soil relative water content presented the same rule ,that was all of them decreased with the increasing of nitrogen application ;but under 300m3/hm2treatment, it achieved the maximum .While under the treatment of W2N3 , the soil relative water content decreased when the nitrogen fertilizer application reached the amount of 138.4 kg/hm2 .Under 600 m3/hm2 treatment, the soil relative water content increased along with the nitrogen application ,which indicated that the tobacco took good advantage on irrigated water and water losing would decrease when the nirogen was excessive applicated .2 The effects of water and nitrogen coupling on tobacco soil chemical contentsNitrogen played a positive part in increasing available nitrogen , which could made fullplay by tobacco ,and compared with nitrogen application ,irrigation played a much more important role .Available phosphorus in soil observed the same law with total nitrogen when considering the depth ,but there was no obvious effect of water-nitrogen interaction on soil phosphorus content .While soil available potassium content presented negative relation with the irrigation amount under the same nitrogen application limits . Under the same nitrogen fertilization treatment level , the organic manure content raised with the increase of irrigation amount ,but under the same irrigation treatment ,organic manure content increased by small margin in the depth rate of 0~20cm along with the increase of nitrogen application ,and regular pattern could rarely be found with the increase of soil depth .3 The effects of water and nitrogen coupling on the activities of soil enzymeThe activities of soil urease and invertase increased with the increase of nitrogen fertilizer application (0~108.4 kg/hm2) ,and it achieved the maximum under the irrigation level of 300 m3/hm2 together with the nitrogen fertilization amount of 108.4 kg/hm2 .The activity of soil protease reduceed as the application of nitrogen increases ,and it achieved the maximum under the irrigation level of 300 m3/hm2 and nitrogen fertilization of 78.4 kg/hm2 .And the regular pattern of the activity of soil enzyme became unremarkable with the increase of soil depth .4 The effects of water and nitrogen coupling on the accumulation of dry matter of flue-cured tobaccoDry matter accumulation under different treatments presented“S”diagram of curves in the field. It was found that dry matter accumulation in different period enhanced along with the increasing of nitrogen fertilizer application both under the irrigation level of 300 m3/hm2 and the higher level of 600 m3/hm2. each treatment reached the maximum amount in 75 days after the transplanting,then decreaseid.Generally speaking,dry matter accumulation under the irrigation of 300m3/hm2 together with nitrogen fertilizer applications that range from 0 to 108.4kg/hm2 reached maximum during the whole growing period of tobacco .5 The effects of water and nitrogen coupling on the qualities of flue-cured tobaccoThe contents of reductive carbohydrate ,total carbohydrate ,starch ,total nitrogen,nicotine and potassium were appropriate while the nitrogen fertilizer applications range from 78.4 kg/hm2 to 108.4 kg/hm2 ,but the ratios of these ingredients harmonizes best when treatment of 108.4 kg/hm2 nitrogen fertilization was applied .So considering irrigation which economizes water a lot ,it could be found that the chemistry elements and inner quality in tobacco leaves could be improved under the irrigation level of 300 m3/hm2 together with the appropriate amount of nitrogen fertilization .6 The effects of water and nitrogen coupling on the content of polyphenols and petroleum ether extracts of flue-cured tobaccoThere were positive correlations between the contents of petroleum ether extract and nitrogen fertilizer application that was not more than 108.4 kg/hm2 ,but the positive correlations between them would turn negative once the amount of nitrogen application raise up to more than 108.4 kg/hm2 .7 The effects of water and nitrogen coupling on the contents of aroma constituents of flue-cured tobaccoIn addition to the treatment without irrigation ,the contents of aromatic phenylalanine and aromatic of other kind present no regular pattern at all to some extent ,and the contents of elements such as carotenoid,phenylalanine ,terpenes,all increased along with the increase of nitrogen application (0~108.4 kg/hm2) ,but all decreased when nitrogen fertilization raised beyond 108.4 kg/hm2 .Total contents of aromatic matter became the largest under W2N3 treatment ,so it was thus clear that there is no advantage to accumulation of total aromatic matter with too much or absolutely without nitrogen application and irrigation .8 The effects of water and nitrogen coupling on the contents of nutrients of flue-cured tobaccoThere were different laws of effect of water and nitrogen coupling using on different mineral elements.Both the contents of Ca an Mg and P decreased when nitrogen fertilizer application increased, and they played an increasing rule when the irrigation amount increased. While the amount of K and P was just on the contrary .When the nitrogen fertilizer application increases ,the contents of B ,Cu ,Fe ,Zn all decreased ,but the contents of Mg increased and when the irrigation amount raised ,the contents of Mg ,B all increased but the contents of Cu ,Fe ,Zn decreased .9 The effects of water and nitrogen coupling on the efficiencies of water application and value application and nitrogen application of flue-cured tobaccoWater utilization ratio of soil increased with the increase of nitrogen under the factor of W2 (except for N4 treatment) ,while W3N3 and W3N4 treatment drive water utilization ratio forward because of their positive effect on yield .Value of output adds along with the increase of nitrogen applications which range from 0 kg/hm2 to 108.4 kg/hm2 ,but it begined decreasing when the amount of nitrogen turns excessive ,so it was with the water utilization ratio ,no matter under the treatment of irrigation or without irrigation at all ,yet treatments of irrigation presented a higher utilization ratio compared with treatments without irrigation under the same nitrogen fertilizer treatment ,and when it reatched its maxmium(600m3/hm2),the nitrogen utilization ratio became decrease.It further indicated that irrigation couled promote both nitrogen element uptake and nitrogen utilization ratio .10 The effects of water and nitrogen coupling on the major economic characters of flue-cured tobaccoThe proportion of first-class tobacco was in positive relation with nitrogen fertilization amounts of 0~108.4 kg/hm2 .But both the proportion of first-class tobacco and the output value decrease while nitrogen application raised up to the amount of 138.4 kg/hm2 (N3) though the tobacco yield increased .The increasing of irrigation amount was positive to enhance tobacco yield ,value of output as well as the proportion of fires-class tobacco .All in all,the irrigation among 300～600m3/hm2 and nitrogen among 108.4～138.4kg/hm2coupling was the best. It was favourable toward achieving the flue-cured tobacco with high-volume、compatible chemical composition and better quality,and it was still in favor of increasing the economic benefits.