Changes in phosphorus （P） fractions in a P deficient allophanic soil under P. radiata seedlings grown with broom （Cytisus scoparius L.） and ryegrass （Lolium multiflorum） in pots were studied 14 months after the ...Changes in phosphorus （P） fractions in a P deficient allophanic soil under P. radiata seedlings grown with broom （Cytisus scoparius L.） and ryegrass （Lolium multiflorum） in pots were studied 14 months after the application of triple superphosphate at the rates of 0, 50, and 100 pg.g^-1, to determine the fate of fertiliser-derived P in the rhizosphere soils. Application of P fertiliser increased NaOH-Pi, NaOH-Po, and H2SO4-Pi concentrations in the soil, but decreased the residual-P concentration. The resin-Pi concentration, which is ex- tremely low in this soil （1 to μgg^-1 ）, remained the same. The majority of the added fertiliser P was however recovered in the NaOH-Pi fraction （40%-49%）. This is due to the high P fixation in this soil （92%）. The second highest P recovery was in NaOH-Po fraction （7%-19%）. Under P deficient condition or addition at the rate of 0 μg.g^-6, the NaOH-Pi concentration in the radiata rhizosphere soil was lower than that in the bulk soil and broom and grass rhizosphere soils. This may be due to higher oxalate production by the roots and mycorrhiza under P deficient conditions which released some ＆the P fixed to the soils in the rhizosphere, which needs to be tested in future studies.展开更多
Changes in phosphorus (P) fractions in a P deficient allophanic soil under P. radiata seedlings grown with broom (Cytisus scoparius L.) and ryegrass (Lolium multiflorum) in pots were studied 14 months after the applic...Changes in phosphorus (P) fractions in a P deficient allophanic soil under P. radiata seedlings grown with broom (Cytisus scoparius L.) and ryegrass (Lolium multiflorum) in pots were studied 14 months after the application of triple superphosphate at the rates of 0, 50, and 100 μg·g-1, to determine the fate of fertiliser-derived P in the rhizosphere soils. Application of P fertiliser increased NaOH-Pi, NaOH-Po, and H2SO4-Pi concentrations in the soil, but decreased the residual-P concentration. The resin-Pi concentration, which is extremely low in this soil (1 to 3 μg·g-1 ), remained the same. The majority of the added fertiliser P was however recovered in the NaOH-Pi fraction (40%?49%). This is due to the high P fixation in this soil (92%). The second highest P recovery was in NaOH-Po fraction (7%?19%). Under P deficient condition or addition at the rate of 0 μg·g-1, the NaOH-Pi concentration in the radiata rhizosphere soil was lower than that in the bulk soil and broom and grass rhizosphere soils. This may be due to higher oxalate production by the roots and mycorrhiza under P deficient conditions which released some of the P fixed to the soils in the rhizosphere, which needs to be tested in future studies.展开更多
Nitrogen(N)enrichment is expected to induce a greater phosphorus(P)limitation,despite the acceleration of soil P cycling.However,the changing patterns in plant P and soil available P after N enrichment,and their regul...Nitrogen(N)enrichment is expected to induce a greater phosphorus(P)limitation,despite the acceleration of soil P cycling.However,the changing patterns in plant P and soil available P after N enrichment,and their regulatory mechanisms,remain poorly understood in alpine meadows.Here,we conducted a field experiment with four N addition rates(0,5,10,and 15 g N m^(-2)yr^(-1))in an alpine meadow,and investigated the P in plants,microorganisms,and soil to determine their patterns of change after short-term N addition.Our results showed that N addition significantly increased plant biomass,and the plant P pool showed a non-linear response to the N addition gradient.Soil available P initially increased and then declined with increasing N addition,whereas the occluded inorganic P decreased markedly.The critical factors for soil available P varied with different N addition rates.At lower N addition levels(0 and 5 g N m^(-2)yr^(-1)),soil acidification facilitated the mobilization of occluded inorganic P to increase soil available P.Conversely,at higher N addition levels(10 and 15 g N m^(-2)yr^(-1)),the elevated soil microbial biomass P intensified the competition with plants for soil P,leading to a decline in soil available P.This study highlights the nonlinear responses of the plant P pool and soil available P concentration to N addition rates.These responses suggest the need for developing ecosystem models to assess different effects of increasing N rates,which would enable more accurate predictions of the plant P supply and soil P cycling under N enrichment.展开更多
Little attention has been paid to how long-term application of crop straw and its biochar affects soil phosphorus(P)transformation and carbon(C)fractions.We conducted a 7-year field experiment including control treatm...Little attention has been paid to how long-term application of crop straw and its biochar affects soil phosphorus(P)transformation and carbon(C)fractions.We conducted a 7-year field experiment including control treatment(chemical fertilizer only,CK),straw return(2.25 t ha^(−1)),and different amounts of biochar addition(11.25 t ha^(−1)(0.5%BC)and 22.5 t ha^(−1)(1.0%BC),to investigate influence of these amendments on soil C structure,P fractions,and their interaction with microorganisms.The 13C nuclear magnetic resonance and soil P sequence fractionation were applied to capture changes of soil C compositions and P pool.Compared to CK,straw and biochar amendments decreased alkyl C/O-alkyl C,which is conducive to increased soil organic C.The 0.5%BC and 1.0%BC treatments enhanced recalcitrant aromatic C by 69.0%and 131%,respectively.Compared to CK(101.2±33.32 mg kg^(−1)),the 0.5%BC and 1.0%BC treatments had a negligible effect on soil available P,while negative effects were observed in straw treatment(59.79±9.023 mg kg^(−1)).Straw and biochar amendments increased primary P and occluded P,whereas had negligible effect on organic P.Redundancy analysis and correlation analysis indi-cated that C compositions and P pool correlated to microbial community composition and enzyme activities,and aromatic C was the most related factor.Moreover,structural equation modeling indicated available P was most related to phosphatase activity and C composition.Our findings reveal the changes of soil P and C response under long-term crop straw and its biochar amendment,and can contribute toward improving understanding of the effect of biochar and straw return in future agriculture management.展开更多
文摘Changes in phosphorus （P） fractions in a P deficient allophanic soil under P. radiata seedlings grown with broom （Cytisus scoparius L.） and ryegrass （Lolium multiflorum） in pots were studied 14 months after the application of triple superphosphate at the rates of 0, 50, and 100 pg.g^-1, to determine the fate of fertiliser-derived P in the rhizosphere soils. Application of P fertiliser increased NaOH-Pi, NaOH-Po, and H2SO4-Pi concentrations in the soil, but decreased the residual-P concentration. The resin-Pi concentration, which is ex- tremely low in this soil （1 to μgg^-1 ）, remained the same. The majority of the added fertiliser P was however recovered in the NaOH-Pi fraction （40%-49%）. This is due to the high P fixation in this soil （92%）. The second highest P recovery was in NaOH-Po fraction （7%-19%）. Under P deficient condition or addition at the rate of 0 μg.g^-6, the NaOH-Pi concentration in the radiata rhizosphere soil was lower than that in the bulk soil and broom and grass rhizosphere soils. This may be due to higher oxalate production by the roots and mycorrhiza under P deficient conditions which released some ＆the P fixed to the soils in the rhizosphere, which needs to be tested in future studies.
基金supported by Centre for Sustainable Forest Management at Forest Research Institute, New Zealand
文摘Changes in phosphorus (P) fractions in a P deficient allophanic soil under P. radiata seedlings grown with broom (Cytisus scoparius L.) and ryegrass (Lolium multiflorum) in pots were studied 14 months after the application of triple superphosphate at the rates of 0, 50, and 100 μg·g-1, to determine the fate of fertiliser-derived P in the rhizosphere soils. Application of P fertiliser increased NaOH-Pi, NaOH-Po, and H2SO4-Pi concentrations in the soil, but decreased the residual-P concentration. The resin-Pi concentration, which is extremely low in this soil (1 to 3 μg·g-1 ), remained the same. The majority of the added fertiliser P was however recovered in the NaOH-Pi fraction (40%?49%). This is due to the high P fixation in this soil (92%). The second highest P recovery was in NaOH-Po fraction (7%?19%). Under P deficient condition or addition at the rate of 0 μg·g-1, the NaOH-Pi concentration in the radiata rhizosphere soil was lower than that in the bulk soil and broom and grass rhizosphere soils. This may be due to higher oxalate production by the roots and mycorrhiza under P deficient conditions which released some of the P fixed to the soils in the rhizosphere, which needs to be tested in future studies.
基金funded by the National Natural Science Foundation of China(31971746 and 32171685)。
文摘Nitrogen(N)enrichment is expected to induce a greater phosphorus(P)limitation,despite the acceleration of soil P cycling.However,the changing patterns in plant P and soil available P after N enrichment,and their regulatory mechanisms,remain poorly understood in alpine meadows.Here,we conducted a field experiment with four N addition rates(0,5,10,and 15 g N m^(-2)yr^(-1))in an alpine meadow,and investigated the P in plants,microorganisms,and soil to determine their patterns of change after short-term N addition.Our results showed that N addition significantly increased plant biomass,and the plant P pool showed a non-linear response to the N addition gradient.Soil available P initially increased and then declined with increasing N addition,whereas the occluded inorganic P decreased markedly.The critical factors for soil available P varied with different N addition rates.At lower N addition levels(0 and 5 g N m^(-2)yr^(-1)),soil acidification facilitated the mobilization of occluded inorganic P to increase soil available P.Conversely,at higher N addition levels(10 and 15 g N m^(-2)yr^(-1)),the elevated soil microbial biomass P intensified the competition with plants for soil P,leading to a decline in soil available P.This study highlights the nonlinear responses of the plant P pool and soil available P concentration to N addition rates.These responses suggest the need for developing ecosystem models to assess different effects of increasing N rates,which would enable more accurate predictions of the plant P supply and soil P cycling under N enrichment.
基金Jiangsu Agriculture Science and Technology Innovation Fund(CX(19)1007)the National Natural Science Foundation of China(No.41671304).
文摘Little attention has been paid to how long-term application of crop straw and its biochar affects soil phosphorus(P)transformation and carbon(C)fractions.We conducted a 7-year field experiment including control treatment(chemical fertilizer only,CK),straw return(2.25 t ha^(−1)),and different amounts of biochar addition(11.25 t ha^(−1)(0.5%BC)and 22.5 t ha^(−1)(1.0%BC),to investigate influence of these amendments on soil C structure,P fractions,and their interaction with microorganisms.The 13C nuclear magnetic resonance and soil P sequence fractionation were applied to capture changes of soil C compositions and P pool.Compared to CK,straw and biochar amendments decreased alkyl C/O-alkyl C,which is conducive to increased soil organic C.The 0.5%BC and 1.0%BC treatments enhanced recalcitrant aromatic C by 69.0%and 131%,respectively.Compared to CK(101.2±33.32 mg kg^(−1)),the 0.5%BC and 1.0%BC treatments had a negligible effect on soil available P,while negative effects were observed in straw treatment(59.79±9.023 mg kg^(−1)).Straw and biochar amendments increased primary P and occluded P,whereas had negligible effect on organic P.Redundancy analysis and correlation analysis indi-cated that C compositions and P pool correlated to microbial community composition and enzyme activities,and aromatic C was the most related factor.Moreover,structural equation modeling indicated available P was most related to phosphatase activity and C composition.Our findings reveal the changes of soil P and C response under long-term crop straw and its biochar amendment,and can contribute toward improving understanding of the effect of biochar and straw return in future agriculture management.
