Effect Of Different Tillage Methods On Transformation Of Phosphorus In Mollisol And Growth Of Maize At Seedling Stage

Mollisol farmland has been suffering predatory farming for a long time,and the problem of poor structure of the plough layer and nutrient content reduction have emerged as in some plots or regions.The level of mechanization is backward,long-term use of the original ridge species.Plough depth is not enough.In order to restore and increase the productivity of mollisol farmland and increase the thickness of live soil layer and soil productivity.Different methods of tillage treating the soil are proposed.And it is also used to explore the effect of different methods of tillage on soil phosphorus content.The growth of maize seedlings and yield.It also make sense in providing scientific basis of the construction of plow layer in the mollisol area and the selection of cultivation techniques for favorable crop growth.The experiment consists of 4 farming treatments:No-tillage?N?,Rotary-tillage?R?,Deep-sown?S?,Deep-turning?D?.Straw is not returned to farmland?N?,and Straw is returned to farmland?S?,Straw returned to field with organic fertilizer?M?.After two years of research on the change and differentiation of phosphorus in 0²0 cm plough layers.The conclusions are as follows:In two years of tillage,effects of tillage methods on soil physical properties were significantly different.Compared with the treatment D,0³0 cm soil layer N increased soil compaction.In2016,subsoiling reduced soil compaction treatment N increased the soil compaction significantly with a maximum of 314.6 kPa respectively,soil compaction decreased the maximum value of220.8 kPa.In 2017,N increased,soil compaction maximum value was 489.3 kPa,SN decreased,soil compaction maximum value was 197.3 kPa.Compared with the treatment D,in 2016,the moisture content ranged from 22.11%³2.78%,treatment N increased the soil moisture content at 0¹0 cm soil layer by 3.19%.For the soil moisture content at the layer of 20 cm⁶0 cm,S with a drop by 6.22%.In 2017,the moisture content ranged from 6.85%³3.26%.N increased the water storage of plough layer?0²0 cm?by 8.62%.Compared with the treatment D,soil temperature of treatment N dropped by 0.7?in 2016 and 1.5?in 2017.Different tillage methods affect soil available phosphorus.R treatment increased soil available phosphorus content in the farming group.It has an average of 10.00 mg.kg^-11 compared with N treatment.Organic fertilizer has obvious effect on improving soil available phosphorus in various farming treatments.RM improves efficiency of available phosphorus in rotary ploughing.Compared with RN,it increased 31.52 mg.kg^-1.Compared with DN,it increased 17.84 mg.kg^-1.Tillage treatment has less effect on soil total phosphorus.Adding organic fertilizer can increase total phosphorus content in soil.Compared with DN,soil total phosphorus content increased 0.131g.kg^-1,0.097 g.kg^-11 and 0.074 g.kg^-11 in DM,SM and RM treatment.Effect of different tillage methods on soil phosphorus composition.The total organic phosphorus content of organic phosphorus deal with N is lower than that of R,S,and D.The mean values of the active organic phosphorus group dealed with N,R,and S are higher than D,and they are 3.06 mg.kg^-11 and 1.84 mg.kg^-1,2.64 mg.kg^-1.Increase compared with D,respectively.After treatment of N,R,S,the Al-P content have increased than D.Fe-P content treated by N is higher than other treatments.The mean Ca-P content in the no-tillage group was lower than other treatments.All treatments has no effect on O-P.The addition of organic fertilizer increased the content of inorganic phosphorus components.The contents of Al-P,Fe-P and Ca-P in RM increase by 58.58%,32.79%and 4.27%.Compared with in RN,respectively.In the treatment of N and D,returning straw to the field reduced the content of Al-P and Ca-P.The slopes of Al-P,Fe-P,Ca-P,active organic phosphorus,medium-active organic phosphorus,high-stable organic phosphorus and available phosphorus are positive,and the iron phosphate has the largest slope coefficient.Effects of different tillage methods on soil phosphorus transformation and enzyme activities.In the tillage group,the intensity of phosphorus conversion of N and S treatments are higher than the D by 0.041 and 0.027,respectively.As to the inorganic phosphorus conversion intensity,the highest is N and the lowest is R.The addition of organic fertilizer have enhanced the phosphorus conversion intensity.And compared with DN,the organic phosphorus conversion intensity of DM increases by 22.00%,and the inorganic phosphorus conversion intensity of DM have increased by11.56%.Acid phosphatase activity of treatment by R is higher than other tillage treatments.In deep pine treatment,compared with SN,SM acid phosphatase in 2016 have increased by 16.74mg.g^-1.d^-1.In 2017,the acid phosphoric acid activity of SM increases by 25.50 mg.g^-1.d^-1,the difference in other treatments is not significant enough.Effects of different tillage measures on seedling growth of corn.The effect of D treatment on the increase of dry weight above ground and root dry weight is the most obvious during maize seedling stage.Compared with N,the D treatment in 2016 increased by 3.92 g and 0.24 g respectively,and increased by 9.85 g and 0.82 g respectively in 2017.Straw returning to farmland reduces the dry weight of corn at the seedling stage for the first year.This can be alleviated by the addition of organic fertilizer.At the seedling stage,the dry weight treatment by RM,RN increases by 1.35 g and 1.06 g,compared with RS,and increased by 1.89 g and 3.03 g for treatment by SM,SN compared with SS.Phosphorus content in maize seedlings showed the greatest effect by deep turning above ground and not significant in the underground.The ear length of corn is ranged from19.61 cm to 20.78 cm,the ear thickness is ranged from 6.40 cm to 7.05 cm,the 100-grain weight range is from 30.17 g to 34.42 g,and the yield range was from 10.84 t·hm^-22 to 14.30 t·hm^-2.Treatment by D in the tillage group the average values are above other tillage group in all of panicle length,panicle thickness,100-grain weight,and grain yield..In summary,the trial area has been transformed from shallow ridge species to four types of tillage treatments.Deep-turning treatment has a moderate effect on physical properties.Deep-turning treatment can effectively increase corn yield and promote the increasing of corn dry weight during seedling stage.Among the three methods of Deep-turning,the application of straw to the field with organic fertilizer can promote the increasing of available phosphorus,increasing the capacity of phosphorus pool,and increasing the content of Al-P,Fe-P,and Ca-P.Under the experimental conditions,the use of deep-turning and straw returning to field with organic fertilizers is more appropriate for the construction of the plow layer in this area.