Tropical Arenosols may be challenging for agricultural use,particularly in semi-arid regions.The aim of this study was to evaluate the impact of the addition of increasing shares of biochar and clay on the nutrient so...Tropical Arenosols may be challenging for agricultural use,particularly in semi-arid regions.The aim of this study was to evaluate the impact of the addition of increasing shares of biochar and clay on the nutrient sorption capacity of a tropical Arenosol.In batch equilibrium experiments,the sorption of ammonium-N(NH_(4)^(+)-N),nitrate-N(NO_(3)^(−)-N),potassium(K^(+)),and phosphate-P(PO_(4)^(3−)-P)was quantified for mixtures of an Arenosol with increasing shares of biochar and clay(1%,2.5%,5%,10%,100%)and the unmixed Arenosol,biochar,and clay.The mid-temperature biochar was produced from Prosopis juliflora feedstock;the clayey material was taken from the sedimentary parent material of a temporarily dry lake.Only the Arenosol-biochar mixture with 10%biochar addition and the biochar increased the NH_(4)^(+)-N maximum sorption capacity(q_(max))of the Arenosol,by 34%and 130%,respectively.The q_(max)of PO_(4)^(3−)-P slightly increased with ascending biochar shares(1-10%)by 14%,30%,26%,and 42%,whereas the undiluted biochar released PO_(4)^(3−)-P.Biochar addition slightly reduced NO_(3)^(−)-N release from the Arenosol but strongly induced K^(+)release.On the other hand,clay addition of 10%and clay itself augmented q_(max)of NH_(4)^(+)-N by 30%and 162%;ascending clay rates(1-100%)increased q_(max)for PO_(4)^(3−)-P by 78%,130%,180%,268%,and 712%.Clay rates above 5%improved K^(+)sorption;however,no q_(max)values could be derived.Sorption of NO_(3)^(−)-N remained unaffected by clay amendment.Overall,clay addition proved to enhance the nutrient sorption capacity of the Arenosol more effectively than biochar;nonetheless,both materials may be promising amendments to meliorate sandy soils for agricultural use in the semi-arid tropics.展开更多
基金the German Federal Ministry of Education and Research(BMBF),Project number 01 LL 0904 A-E.
文摘Tropical Arenosols may be challenging for agricultural use,particularly in semi-arid regions.The aim of this study was to evaluate the impact of the addition of increasing shares of biochar and clay on the nutrient sorption capacity of a tropical Arenosol.In batch equilibrium experiments,the sorption of ammonium-N(NH_(4)^(+)-N),nitrate-N(NO_(3)^(−)-N),potassium(K^(+)),and phosphate-P(PO_(4)^(3−)-P)was quantified for mixtures of an Arenosol with increasing shares of biochar and clay(1%,2.5%,5%,10%,100%)and the unmixed Arenosol,biochar,and clay.The mid-temperature biochar was produced from Prosopis juliflora feedstock;the clayey material was taken from the sedimentary parent material of a temporarily dry lake.Only the Arenosol-biochar mixture with 10%biochar addition and the biochar increased the NH_(4)^(+)-N maximum sorption capacity(q_(max))of the Arenosol,by 34%and 130%,respectively.The q_(max)of PO_(4)^(3−)-P slightly increased with ascending biochar shares(1-10%)by 14%,30%,26%,and 42%,whereas the undiluted biochar released PO_(4)^(3−)-P.Biochar addition slightly reduced NO_(3)^(−)-N release from the Arenosol but strongly induced K^(+)release.On the other hand,clay addition of 10%and clay itself augmented q_(max)of NH_(4)^(+)-N by 30%and 162%;ascending clay rates(1-100%)increased q_(max)for PO_(4)^(3−)-P by 78%,130%,180%,268%,and 712%.Clay rates above 5%improved K^(+)sorption;however,no q_(max)values could be derived.Sorption of NO_(3)^(−)-N remained unaffected by clay amendment.Overall,clay addition proved to enhance the nutrient sorption capacity of the Arenosol more effectively than biochar;nonetheless,both materials may be promising amendments to meliorate sandy soils for agricultural use in the semi-arid tropics.
