Tillage effects on soil carbon balance in a semiarid agroecosystem

BONO, A.; ALVAREZ, ROBERTO; BUSCHIAZZO, D. E.; CANTET, R.J.C.

SOIL SCIENCE SOCIETY OF AMERICA JOURNAL

Año: 2008 vol. 72 p. 1140 - 1149

0361-5995

Tillage systemsm ¿y xffecrs oil c sequesrrationr,v ith a potential impa* on crop producrivity or or:ganicm atter rnineralization.V e evaluatetcl rop vield.,C inputs to ¡he soil, and in situ COr-C fluxes under no-till and convcntional ¡illase (c{isk tillagc) during the 3- ro (í-yr period From the insrallation oi an experiment in an llntic Haplustoll ofr rhe Senriarid PampeanR egion of Argendn,r io elucid¡.te¡ he rnechanis¡nsr elsponsiblclo r possiblem anaglement´indrrcedso il or:ganicn ratrer changes.Y ield ¿nd binmassp roduction were grearer under rro-LillL lrrrnd isk tillege [or all the crops included in thc rot:rrion (oat lAtmn satíua l..l + hairy ver.c l/iria uillos¿ Roth ssp. uillosaj, corn lZea mays 1..j. wheat l´liiricmn aestiuum L.l, lnd oat). This resulr was atrribrLttd to the higber soil rvater conLenr u¡rder no-dll. Carbon inputs to ¡he soil averascd4 lVlSC hr-l r.-l r-rndern o-till an<l3 Ms 1- ¡r*-l y¡-l under disk tillage. Soil temperature r¡´as similar lretween tillage sletems arrd [iOr-Cl emission lvas about 4 Mg ¡ 1tn- i trt . wirh significant br.rt small differcnces bern een ,i."r-"rr., (-0.2 Mg c ha-l y,:-1). (-lalbon balance of rhe snil rvas nearly equili!rarerl uncler no-rill; tneauu4riltlg, reaterC lossesa s CO, than inprLtsi rr crop residucsw erc lnerrsuretul nclerc onvenrionalr illa.geo.r ganic C in ¡he soilw ¡s 5.4 lr4gh a-t higherL rndenr o-till rb¡n dred isk tillege treatmcnr 6 yr ellcr init.iationo f the experimenr. Resuitss horvecri liar in otLrs emlarid envirolLme¡rtC, sequestr;ltiono ccurredu nder no-rill bur ¡ror conventionalt illage.´l´he sequestrationp rocessw as ac¡rilrLLterdo rhe effec¡o f rhe tillage systenre n crop protlucrivrq, rather than on the mineralization intensity´ofsoil organic poois-