| Object: Processing tomato is an important economic crop in Xinjiang.Because most of the current conventional varieties are not salt-tolerant,Xinjiang has a large area of saline-alkali land and saline-alkali wasteland.In order to expand the planting area of processed tomatoes and increase the output value of processed tomatoes in the whole region,It is necessary to promote the processing of processed tomatoes to saline-alkali soil.However,there are few studies on the reasonable soil salt content that can be processed by tomato and the economical and reasonable amount of fertilizer applied in saline-alkali soil.Therefore,this paper studies the processing of potted plants in 2017-2018 for two years.The changes of growth physiology of tomato under different nitrogen application rate and soil salt content and the reasonable nitrogen application rate and soil salt content of processed tomato to obtain the highest yield and the best quality were determined by reasonable data analysis.The effect model gives reasonable fertilizer effect equations for different soil salinity levels and explores the effects of different soil salt content changes on the growth physiological indexes of processed tomato.Methods: From 2017 to 2018,the water-saving test station of Shihezi University carried out the processing of tomato potting.The test seedlings were the main cultivated variety “3166”.The annual irrigation period of the two-year experimental tomato processing was 450 mm,and the soil salt content in 2017 was set.The four levels are CK: 1.5 g·kg-1,S1: 4.0 g·kg-1,S2: 7.0 g·kg-1,S3: 10.0 g·kg-1,and the nitrogen application rate is urea 225 during the whole growth period.Kg/hm2 is conventional nitrogen application,and four levels are set and converted into single pot nitrogen application,respectively: N1: 8.92 g·pot-1,N2: 7.12 g·pot-1,N3: 5.35 g·pot-1,N4 :3.57 g·Pant-1,the experimental design of 2018 has been improved based on 2017.According to the first year test analysis,S3: 10.0 g·kg-1 was removed at the salt level in the second year,and 5.0 g·kg-1 was added,so the soil salinity treatment in 2018 is: CK: 1.5 g·kg-1,S1: 4.0 g·kg-1,SS2: 5.0 g·kg-1,SS3: 7.0 g·kg-1,Nitrogen application rate was added to N0:0 g·pot-1 on the basis of the first year,and the rest was consistent with the first year.Irrigation was carried out 9 times during the whole growth period,and fertilization was carried out 8 times.Results:?1?The soil moisture content of processed tomato increased with the increase of soil salt content and soil depth,and decreased in the main root zone,reaching the maximum water content at 10 g·kg-1 and 7 g·kg-1 for two years.The depth of the soil layer reached the maximum water content at 40 cm depth 7 days after irrigation.The combination of low nitrogen and high salt will increase the water absorption capacity of processed tomato roots and promote the growth of processed tomatoes.Nitrogen had no significant effect on the moisture content and salinity of processed tomato soil.On the 7th day after irrigation,the soil salt content mainly accumulated in the soil layer of 30-40 cm.The planting soil of processed tomato in the whole growth period was in slow desalting state.And the higher the soil salt content,the more significant the desalination effect.?2?Under the combined effect of nitrogen and soil salinity,the plant height,leaf area index,photosynthetic rate,stomatal conductance,maximum photochemical efficiency of PS II,actual photochemical efficiency and non-photochemical quenching coefficient of processed tomatoes were the highest in the low-salt region(1.5-4.0 g.kg-1)and the highest in the medium-high-salt region(7.0-10.0 g.kg-1).Low nitrogen treatment?3.57 g.pot-1?had the greatest effect on processing tomatoes.Among all soil salt treatments,normal nitrogen application?5.35 g.pot-1?had the worst effect on processing tomatoes.?3?Fresh fruit yield of processed tomatoes is generally characterized by "high yield of salt is low,low yield of salt is high.".However,due to the interaction between salt and nitrogen,the yield of processed tomatoes under low nitrogen and high salt condition is higher than that under other nitrogen levels,but the maximum yield of processed tomatoes still appears at medium to high nitrogen application level and low salt treatment;soluble solids,vitamin C,soluble sugar and cocoa.Titrating acid increased gradually with the increase of soil salt content.The first three decreased gradually when the soil salt content was too high(10 g.kg-1),but the triable acid still increased.The highest sugar-acid ratio appeared at low salt(4 g.kg-1).The effect of nitrogen on the quality of processed tomatoes was not significant.The interaction of the two could not make the processing of tomatoes between different treatments.There are significant differences in quality.After comprehensive consideration of the intervals obtained from the two-year experiment,the most reasonable intervals of nitrogen application and soil salt content were determined as follows: N [2.20,4,76]?g.pot-1?,namely N [154.63,200.55]?kg·hm-2?,S [3.56,5.59](g.kg-1).?4?The changes of net photosynthetic rate,transpiration rate and stomatal conductance of processed tomato were basically the same,all of them reached the maximum around 12:00-14:00,and the light intensity was weak at 10:00 and 18:00.The minimum value is reached to the left and right,and the degree of influence of soil salt content on it is S1>CK>S2>S3.The diurnal variation of intercellular CO2 concentration is opposite to the first three.The medium and heavy saline-alkaline soils of 7.0 and 10 g·kg-1 had an early growth period for the processing of tomato compared with the mild saline-alkali soil of 4 g·kg-1.The soil salt content of 4.0 g·kg-1 was better than that of 7.0 and 10 g·kg-1,which could promote the growth,physiological indexes and water and fertilizer use efficiency of processed tomato.In the 2018 test design,5.0 g·kg-1 The soil salt content of-1 does not promote the growth of processed tomato like 4.0 g·kg-1.It has a certain inhibitory effect on the growth physiology of processed tomato,and the degree of inhibition is close to that of 7.0 g·kg-1.?5?By establishing different nitrogen one-element effect models,the nitrogen effect model of non-saline alkaline soil and weak saline-alkali soil suitable for linear plus platform is obtained,and the nitrogen effect model of moderate saline-alkali soil is suitable for square root.The nitrogen application rates of the three types of saline-alkali soils were as follows: non-salt alkaline soil: 8.474 g·pot-1,weak saline-alkali soil: 8.625 g·pot-1,moderate saline-alkali soil 1.402 g·pot-1 The simulated value is close to the measured value,and the obtained model can better predict the reasonable nitrogen application rate of processed tomato in different salinity levels.Conclusion: During the whole growth period,the soils planted for processing tomatoes were in a slow desalination state,and the higher the salt content of the soil,the more significant the desalination effect was.The effects of nitrogen-salt interaction on the Growth Physiological Indexes of processing tomatoes were as follows: medium and high nitrogen application?7.12 g·pot-1?had the greatest promotion on processing tomatoes,in medium and high salt areas(7.0-10.0 g·kg-1),and low nitrogen treatment?3.57 g·pot-1?had the greatest promotion on processing tomatoes.Solanaceae promoted the most,and the change of yield index was consistent with the change rule of growth physiological index.After comprehensive consideration of the interval obtained from two years' experiment,the most reasonable range of nitrogen application and soil salt content was determined as follows: N [3.67,4,76]?g·pot-1?,i.e.N [154.63,200.55]?kg·hm-2?,S [3.56,5.59](g·kg-1).By establishing different single-effect models of nitrogen,nonfertilizer was obtained.Saline-alkali soils and weak saline-alkali soils are suitable for linear plus platform nitrogen effect model,while moderate saline-alkali soils are suitable for square root nitrogen effect model. |
PDF Full Text Request