Cover crops affect the soil chemical properties under no-till system

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1 AJCS 1(8): (216) DOI: /js p748 ISSN: Cover rops ffet the soil hemil properties under no-till system Simone Cândido Ensins 1, Ademr Pereir Serr* 2, Mrlene Estevão Mrhetti 1, Eulene Frniso d Silv 3, Eline Reis Pinheiro Lourente 1, Eer Augusto Ferreir do Prdo 1, Flávi Arújo Mtos 1, Pedro Henrique Altomr 1, Mtheus Andrde Mrtinez 1, Dougls Cost Potrih 1, Vness do Amrl Conrd 1, Mílson Vieir Jesus 1, Tárik Czeiro El Kdri 1 1 Universidde Federl d Grnde Dourdos (UFGD), City of Dourdos, Stte of Mto Grosso do Sul, Brzil 2 Brzilin Agriulturl Reserh Corportion (EMBRAPA), City of Cmpo Grnde, Stte of Mto Grosso do Sul, Brzil 3 Fuldde de Ciênis Agráris/Universidde Federl Rurl do Semi-Árido (UFERSA), City of Mossoró, Stte of Rio Grnde do Norte, Brzil *Corresponding uthor: demr.serr@emrp.r Astrt The purpose of this study ws to ssess the hnges in soil hemil properties ffeted y the over rops ultivted in rop rottion in short-term of no-till implementtion under Rhodi Hpludox soil. This reserh ws rried out from Otoer 21 to Ferury 214. The experiment ws set up in ompletely rndomized loks in ftoril design with eight tretments (over rops) nd three soil depths (, nd m) with four repetitions. The over rops were: fll-winter mize (T 1 ), interropping fll-winter mize with B. ruziziensis (T 2 ), interropping fll-winter mize with B. riznth v. Mrndu (T 3 ), interropping fll-winter mize with Crotlri spetilis (T 4 ), B. ruziziensis (T 5 ), B. riznth v. Mrndu (T 6 ), Pennisetum gluum L. (T 7 ) nd fllow (T 8 ). The T 6 nd T 7 ffeted exhngele Mg +2, it ws oserved higher exhngele Mg +2 in T 6 (2.39 mol nd T 7 (2.43 mol in omprison to T 1. The phosphorus ontent showed intertive effet etween over rops nd soil depth. In the omprison mong the depths, the P ontents were higher in m, whih showed improvement of 24.6% nd 25.2% in omprison to nd m lyers, respetively. The over rops evluted in this reserh ffeted the exhngele Mg +2 nd K +, s well s Mg +2 nd K + sturtion. The P ontent hnged in response of over rops, whih ws importnt to oserve tht this nutrient my inrese the ontent with doption of over rops in no-till system. The speies used in this reserh might e reommended to integrte rop rottion system with the possiility of inresing P vilility in topsoil depth in no-till system. Keywords: Sustinility, phosphorus ontent, soil fertility, rop rottion. Arevitions: Mg h -1 _ton h -1 ; CEC_Ction Exhnge Cpity. Introdution In Brzilin svnnh Cerrdo, reserhers re looking for onservtive system of griulturl tht promotes improvement in soil hemil, physil nd iologil properties, in this point of view, the no-till system shows to e gret option to gurntee the sustinility of soil used in griulturl system (Sá et l., 214; Dng et l., 215). An importnt step to implement no-till system is the hoie of the over rops speies to ompile the rop rottion system, euse in Brzilin Cerrdo iome, the wether ondition is quite limited during fll-winter seson nd it my dely the prodution nd mintenne of rop residues elowground nd oveground. It is possile tht, speies in rop rottion might promote hnges in soil hemil properties (Lndry et l., 214). euse plnts n uptke the nutrients in soil deeper lyers nd deposit in topsoil, reyling the nutrients in soil. The oveground dry mtter n relese the nutrients from plnt tissues through the proess of minerliztion; this proess n hnge the dynmi of nutrients in the soil, ording to Dud et l. (23). The minerliztion of SOM my relese orgni id tht n omplex the exhngele luminum nd mngnese, whih might derese the toxi effet for plnts (Zmrosi et l., 28; Eimil-Frg et l., 215). Different root depth development of eh speies in rop rottion might ontriute to inrese nutrients vilility in soil solution (Gri et l., 28; Clegri et l., 213; Rosolem nd Clonego, 213). Some reserhes indite the possiility of over rops residues hnging the hemil soil, s the se of Bssegio et l. (215) who oserved tht millet in rop rottion hs higher verge of exhngele potssium. The ultivtion of different speies of plnts n modify the nutrients dynmi in soil (Tieher et l., 212; Steiner et l., 212; Lndry et l., 214). On one hnd there re reserhes tht indite positive results nd improvement of hemil soil through the over rops; on the other hnd reserhes tht did not oserve ny differene in hemil soil properties (Moreti et l., 27; Cunh et l., 211). In the stte of Mto Grosso do Sul, Brzil, the millet (Pennisetum merinum L.), Crotlri spetilis nd forge grss (Brhiri spp.) re the over rops options tht hve een used y frmers. The interropping mize with 114

2 Brhiri spp. is n importnt system of prodution tht must e well-known to e possile the implementtion fousing on the enefits tht this interropping my ring into n griulturl system of prodution. However, due to the limited numer of informtion out the soil hemil properties tht re ffeted y these over rops in interropping, it is importnt to develop reserhes to understnd the enefits or not of these systems. Espeilly out phosphorus ontent in soil, euse in Brzilin Cerrdo the low phosphorus ontent in soil is hllenge to otin sustinility in griulturl system. Bsed on the point of view ove, the purpose of this study ws to ssess in short-term of no-till implementtion the hnges in hemil properties ffeted y the over rops ultivted in rop rottion under Rhodi Hpludox soil. Results nd disussion Anlysis of vrine (ANOVA) of the prmeters ssessed It ws tken the joint nlysis to study the effets of over rops nd soil depths on soil hemil properties. Signifint intertion (p.1) etween over rops nd soil depths for phosphorus ontent in soil ws otined. There were effets (p.1) of over rops on exhngele mgnesium, exhngele potssium, mgnesium sturtion nd potssium sturtion. In reltion to soil depths, it ws oserved signifint effets (p.1) for ll vriles ssessed in this study. Soil depth effets on soil hemil properties The soil idity inresed in deeper depth, tht ws oserved higher vlues of soil ph in topsoil ( m depth) (Fig 1). The potentil idity (H+Al) nd exhngele luminum showed higher vlues in m depth, whih differed sttistilly (p.1) from the topsoil (Fig 1). Due to no-till system, the liming is rodst in soil surfe; this pplition my derese the effets of liming in deeper lyers. Even with the inorportion of liming in the eginning of the experiment implementtion in soil profile of -2 m, this effet is not long lsting. As reported y Clegri et l. (213), in evlution of long-term experiment, the rodst of liming on soil surfe in no-till system ws not effiient to orret the soil ph nd luminum exhngele in deeper lyers. This effet of deresing soil ph in deeper lyer is not oserved in ll ses, euse in no-till system evluted y Adollhi nd Munkholm (213), the vlue of soil ph inresed in deeper lyer ( m). The exhngele C +2 nd Mg +2 dereses through the soil profile, tht n e ssoited with the result of deresing soil ph (Fig 1). In generl, the exhngele C +2, Mg +2 nd K +, CEC, se sturtion nd sum of se showed higher vlue in topsoil (- 5 m) thn in deeper lyer ( m) (Fig 1). The inrese of se sturtion is ssoited with the liming surfe rodst nd potssium in roplnds, this wy the umultion of nutrients (C +2, Mg +2 nd K + ) in topsoil n e inresed over time. Higher nutrient onentrtion in topsoil in no-till system ws oserved y Rheinheimer nd Anghinoni (23) nd Agede (21). It ws oserved y Willekens et l. (214) nd Gri et l. (28) tht potssium showed higher onentrtion in no-till system in topsoil thn in deeper lyer. These uthors suggested tht this inrese ws ssoited with the rop residues in no-till system nd pity of nutrients reyling y plnts, promoting the no exhngele potssium to exhngele potssium, inresing the viility for plnts uptke. The umultion of nutrients in topsoil nd tion exhnge pity (CEC) in no-till system n e ssoited with nottill nd mintenne of rop residues on soil surfe, this leds to inrese SOM (D'Hene et l., 29). The CEC in Oxisol is very dependle of orgni olloids, whih implies tht SOM my inrese the CEC. Even with no differene oserved for over rops effets on CEC in this study, it is importnt to emphsize tht ll over rops produed oveground dry mtter in high quntity (ove 4 Mg h -1 ) tht remined in the soil surfe overed (dt not showed). This input of SOM my ontriute to inrese CEC in topsoil, ut, it is importnt tht CEC inreses in deeper lyer s well, nd this is hllenge for soil sientist. Bse sturtion, luminum, hydrogen, lium, mgnesium nd potssium sturtion effets y soil depth Aluminum nd hydrogen sturtion inrese in deeper lyers, this effet ought to e ssoited with deresing in se sturtion nd ph in deeper lyers (Fig 2). The effets of liming in deeper lyers in no-till system is limited euse of the sene of tillge, this wy the ronte dereses in deeper lyers nd luminum nd hydrogen tke ple in CEC. With the impossiility of ple lime in deeper lyers in no-till system fter implementtion, the ronte tends to derese over time. As reported y Wng et l. (215), the derese of ronte in soil tends to inrese the idifition, whih results in inresing Al +3 nd H + sturtion in soil. The lium, potssium nd mgnesium sturtion were higher in topsoil, whih differed from the other lyers evluted (Fig 2). Effets of over rops on exhngele nd sturtion of mgnesium nd potssium On one hnd, the tretment T 6 nd T 7 effets on exhngele Mg +2, whih ws oserved higher exhngele Mg +2 in T 6 (2.39 mol dm -1 ) nd T 7 (2.43 mol dm -1 ) in omprison to T 1, on the other hnd, the T 6 nd T 7 did not differ from the other tretments (Fig 3). In reltion to the mgnesium sturtion, the highest vlue (2.19%) ws oserved in the T 6, whih showed signifint differene (.1) from T 1, T 2 nd T 4, however the T 6 did not differ from T 3, T 5, T 7 nd T 8 (Fig 3). Higher vlues of sturtion nd exhngele Mg +2 in the T 6 nd T 7 n e n inditive of these over rops pity in promoting inrese of mgnesium in soil profile (-2 m depth). The gretest performne of these speies of over rops n e ssoited with the highest dptility in Cerrdo soil in Brzil, most of these speies show deep root in soil nd onstntly renew their roots, furthermore these speies hve higher pity in iomss prodution tht n e le to produe high quntity of iomss nd inrese SOM nd nutrients ontent in soil. As reported y Tilmn et l. (21), the diversity of speies inrese ron stoks nd enefit the soil qulity muh higher thn monoulture. It is possile tht Brhiri riznth v. Mrndu (T 6 ) nd millet (T 7 ) re more effiient in mgnesium uptke nd umultion in their tissue. As reported y Torres et l. (28), the Brhiri riznth v. Mrndu nd millet showed higher mgnesium ontent in their residues, 21.1 kg h -1 nd 22.6 kg h -1, respetively. The pity of millet in promoting the highest vlue of exhngele Mg +2 ws oserved y Andrioli nd Prdo (212). In reltion to exhngele K +, the highest ontent ws oserved in T 8, whih differed from the T 4, T 6 nd T 7, however, there ws no differene in reltion to T 4, T 6 nd T 7 (Fig 3). To K + sturtion, the highest vlue ws oserved in 115

3 Tle 1. Some physil nd hemil soil properties of the experimentl site. Depths -2 m 2-4 m ph (CCl 2 ) SOM (g P (mg K + (mol.41.1 C 2+ (mol Mg 2+ (mol H+Al (mol Al 3+ (mol.34 SB (mol CEC (mol BS (%) Cly (g kg -1 ) 39 Snd (g kg -1 ) 31 Silt (g kg -1 ) 3 CEC: Ction Exhnge Cpity; totl idity ph 7. (H + +Al +3 ); Exhngele (KCl 1 mol L -1 ) C +2, Mg +2 nd Al +3 ; SB: Sum of Bse= tions; BS: Bse Sturtion=( tions/cec)x1. Tle 2. Tretments desription. Tretments (T) Cover rops Spring-summer seson T 1 Fll-winter mize Soyen T 2 Interropping fll-winter mize with B. ruziziensis Soyen T 3 Interropping fll-winter mize with B. riznth v. Mrndu Soyen T 4 Interropping fll-winter mize with Crotlri spetilis Soyen T 5 Brhiri ruziziensis Soyen T 6 Brhiri riznth v. Mrndu Soyen T 7 Pennisetum gluum L. Soyen T 8 fllow Soyen T 8, whih differed from the T 5, T 6 nd T 4, however there ws no differene in omprison to T 1, T 2, T 3 nd T 4 (Fig 3). The highest exhngele K + in T 8 might e due to the sene of over rops, tht resulted in low nutrient requirement nd reyling from deeper soil. Besides, in the re with over rops, the highest prt of potssium in the system soil nd plnt my e immoilized y plnts deresing the exhngele potssium in soil (Rosolem nd Clonego, 213), ut this potssium n eome exhngele through the minerliztion proess in soil. Cover rops nd soil depth effets on phosphorus ontent in no-till system The P ontent showed intertive effet etween over rops nd soil depth (Fig 4). In omprison mong the over rops, the T 7 (millet) deresed the phosphorus ontent in nd 5-1 m lyer, in omprison with the other over rops. The millet is n dptle rop in temperte regions, due to high root system nd pity of extrt high quntity of nutrients from soil solution, espeilly phosphorus nd potssium (Molin et l., 2); these effets results in high mount of phosphorus in plnt tissue deresing in soil (Foloni et l., 28). However, it is importnt to keep in mind tht this dereses in phosphorus ontent does not men in phosphorus lost, euse with minerliztion of rop residues this phosphorus my return into the soil. The T 1 showed the highest phosphorus ontent in the lyer m, it showed signifintly differene (p.1) in reltion to the lyers nd m. In the T 5, the phosphorus ontent ws higher until 1 m lyer. In T 6 (B. riznth v. Mrndu), the highest phosphorus ontent ws oserved in m lyer (Fig 4). In generl, in the omprison mong the three depths evluted, the phosphorus ontents were higher in m, whih showed improvement of 24.6% nd 25.2% in omprison to nd m lyers, respetively (Fig 4). The highest phosphorus ontent might e ttriuted to the no-till system nd mintenne of rop residues on soil surfe (Bssegio et l., 215), nd nother possile explntion for phosphorus ontent in m is the fertiliztion in the rows rops in this soil lyer ( m). In generl, onsidering the nutrient rnge optimum in soil for plnt development, it ws verified in this reserh tht the fertilizer pplied ssoited with the over rops in no-till system inresed the exhngele C +2, Mg +2, K + nd sum of se, whih ws dequte for plnt development. In reltion to CEC, se sturtion nd soil ph until 1 m depth showed dequte vlues nd the potentil idity (H+Al) ws onsidered n verge rnge vlue. The exhngele Al +3 nd ph elow 1 m depth were lssified s low sore nd phosphorus ontent oserved in the soil ws ove the ritil vlue (9 mg (Rieiro et l., 1999). The utiliztion of over rops improved soil hemil in notill system through the inresing of ville nutrients, whih is importnt to redue the spending with fertilizer through the pplition of informtion like in this reserh to mnge the nutrients in no-till system. Mterils nd methods Site desription This reserh ws rried out from Otoer 21 to Septemer 213 in Rhodi Hpludox, lyey texture, ly minerlogy is onstituted minly y Al/Fe oxy-hydroxides, ording to txonomy of Sntos et l. (213), loted in the muniiplity of Mrju, Stte of Mto Grosso do Sul, Brzil (pproximtely S W, verge ltitude 384 m ove se level). Aording to Köppen (1948), the region is lssified s tropil limte of type Cw, with 116

4 ph CCl H+Al (mol Al +3 (mol Exhngele C +2 (mol Exhngele Mg +2 (mol Exhngele K + (mg Ction Exhnge Cpity (mol Bse sturtion (%) Fig 1. Soil hemil properties. Different letters indite signifint differene (p.5) mong depths y Tukey test of mens. The error rs re the stndrd errors. 117

5 .5 Aluminium sturtion (%) Hidrogen sturtion (%) Clium sturtion (%) Mgnesium sturtion (%) Potssium sturtion (%) Sum of se (mol Fig 2. Soil hemil properties. Different letters indite signifint differene (p.5) mong depths y Tukey test of mens. The error rs re the stndrd errors. riny summer nd dry winter. The rinfll nd temperture in the region of the experimentl site is showed in Fig. 5. Histori of the re During ten yers, the experimentl re ws ultivted with soyen in spring-summer nd mize in fll-winter seson. Before the implementtion of the experiment in June 2 th 21, it ws olleted soil to nlysis the hemil nd physil properties, in -2 nd 2-4 m depth (Tle 1). The dolomiti lime (2.4 Mg h -1 ) nd gypsum (CSO 4.2H 2 O) (.6 Mg h -1 ) were pplied in 21, 3 dys efore soyens sowed. The lime showed lium ronte equivlent (CCE) to 64%. The lime nd gypsum were omplished y spreding on the soil without inorportion. Experimentl design nd tretments The experiment ws rried out during three yers, from 21 to 213. The ssessments of the experiment were performed in Septemer 213. The experimentl design ws set up in ompletely rndomized loks with eight tretments (over rops) nd in three soil depths (, nd m) with four repetitions (Tle 3). The experimentl unit ws set in dimension of 12 m x 2.5 m. The tretments dopted were different over rops sowed in the fll-winter seson efore soyen ultivtion in the spring-summer seson under no-till system (Tle 2). Plnt mteril nd steps of tretments implementtion The mjor speies in the fllow were silly for the weeds for Bidens pilos, Eleusine indi, Euphori heterophyll, Brhiri spp. nd Ipomoe grndifoli. The sowing of the fll-winter orn in the growing sesons ws omplished in no-till system right fter the soyen hrvest. It ws used the fll-winter orn hyrid DKB 39 VTPRO. The sowing of fll-winter orn ws exeuted depositing three seeds per meter in the sping etween rows of 5 m. At the moment of sowing in Ferury of eh yer, the fertilizer ws omplished with 256 kg h -1 of the formultion (N-P 2 O 5 -K 2 O), this fertilizer reommendtion ws sed on the results of soil hemil nd dequte nutrient rnge ording to Cntruttti et l. (1999). The interropping fll-winter mize with forges grss (B. ruzizienses nd B. riznth v. Mrndu) ws sowed t the sme moment through the use of utomtized mhine. The spe etween rows for forges grss ws 21 m. The seed ulturl vlue for B. ruzizienses nd B. riznth v. Mrndu were 5% nd 8%, respetively. Both speies of forges grss showed seeds with 8% of germintion nd 62.5% of purity. To estlish the interropping fll-winter 118

6 Exhngele Mg +2 (mol Mgnesium sturtion (%) T 1 T 2 T 3 T 4 T 5 T 6 T 7 T 8 T 1 T 2 T 3 T 4 T 5 T 6 T 7 T 8 Cover rops Cover rops Exhngele K + (mg Potssium sturtion (%) T 1 T 2 T 3 T 4 T 5 T 6 T 7 T 8 T 1 T 2 T 3 T 4 T 5 T 6 T 7 T 8 Cover rops Fig 3. Cover rops effets on exhngele nd sturtion mgnesium nd potssium. Different letters indite signifint differene (p.5) mong over rop y Tukey test of mens. The error rs re the stndrd errors. T 1 _Fll-winter mize; T 2 _Interropping fll-winter mize with B. ruziziensis; T 3 _Interropping fll-winter mize with B. riznth v. Mrndu; T 4 _Interropping fll-winter mize with Crotlri spetilis; T 5 _B. ruziziensis; T 6 _B. riznth v. Mrndu; T 7 _Pennisetum gluum L.; T 8 _ fllow. Cover rops Phosphorus (mg m depth m depth m depth A A A A A B BA A A A A A A A A A A B A B A A B Cover rops (Tretments-T) Fig 4. Intertion effets etween over rops nd soil depths on phosphorus ontent in soil. Different upperse letters indite signifint differene (p.5) mong depths within sme over rop while different lowerse letters indite signifint differene (p.5) mong over rop y Tukey test of mens. The error rs re the stndrd errors. T 1 _Fll-winter mize; T 2 _Interropping fll-winter mize with B. ruziziensis; T 3 _Interropping fll-winter mize with B. riznth v. Mrndu; T 4 _Interropping fll-winter mize with Crotlri spetilis; T 5 _B. ruziziensis; T 6 _B. riznth v. Mrndu; T 7 _Pennisetum gluum L.; T 8 _ fllow. Air temperture ( C) 4 Rinfll 35 Temp Min Temp Mx Rinfll (mm) Strt in June 21 End in Ferury 214 Cropping seson Fig 5. Monthly rinfll nd temperture in the period from June 21 to Ferury

7 orn with B. ruzizienses nd B. riznth v. Mrndu, it ws used 3. nd 3.5 kg h -1 of pure life seeds, respetively. The plots sowed with only B. ruziziensis nd B. riznth v. Mrndu were estlished with 4. nd 5. kg h -1 of pure life seeds, respetively. The P. gluum L. sowing ws omplished in the spe etween rows of 5 m. The P. gluum L. ultivr sowed ws BRS 151, whih ws used 11 kg h -1 of seeds. The interropping fll-winter orn with C. spetilis ws omplished with 6 kg h -1 of seeds in the spe etween rows of 45 m. The sowing of C. spetilis ws done mnully 15 dys fter the winter orn sowed. In the soyen sowing it ws used n utomtized mhine. In the osion of sowing in Otoer of eh yer, it ws omplished the fertilizer with 38 kg h -1 of the formultion (N-P 2 O 5 -K 2 O) in sowing furrow, this fertilizer reommendtion ws sed on soil hemil results nd soyen needs ording to Cntruttti et l. (1999). The soyen ultivr sowed ws BMX Potêni Roundup Redy (99% of purity nd 95% of germintion). It ws sowed 15 seeds per meter. The soyen seeds were treted with fungiide [Croxin + Thirn (48 g L -1 )], insetiide [Fipronil (4 g L -1 )], mironutrients [olt (2.32 g L -1 ) nd molydenum (4.6 g L -1 )], nd these doses were in grm of tive ingredient per 8 kg of seeds. Besides, the seeds were inoulted efore the sowing with inoulte in turf, whih ontented the teri Brdyrhizoium elkni (Re Semi 519) nd Brdyrhizoium jponium (Re Semi 579) in the onentrtion of 5x1 9 vile ells per grm of inoulte. It ws used 1 ml of inoulte in eh 8 kg of soyen seed. The desition of over rops ws omplished 2 dys efore the soyen sowing, through the use of glyphoste-slt-isopropylmine (1,44 g h -1 of id equivlent) plus 1,29 g h -1 of tive ingredient of 2.4-D, dimethylmine slt. Soil mesurement Soil smples were olleted fter desition of over rops in Septemer 213. The mesurements were tken in three soil depths (, nd m). The smples were olleted in trenhes. These trenhes were mde perpendiulr to the sowing row. After olleting the omposite soil smple, it ws stored in plsti g, identified nd forwrd to Soil L of Universidde Federl d Grnde Dourdos (UFGD) in Brzil to e nlyzed. The following prmeters were evluted in the soil smple; ph CCl2 (1:2.5 rtio), totl idity ph 7. (H + +Al 3+ ), phosphorus ontent, exhngele potssium, exhngele luminum, exhngele lium, exhngele mgnesium, se sturtion, Ction Exhnge Cpity (CEC) in ph=7., se sturtion (BS%), lium (%C), mgnesium (%Mg), potssium sturtion (%K), following the methodology of Clessen (1997). Sttistil nlysis The vriles ssessed in this experiment were sumitted to the nlysis of vrine (ANOVA) y the F-test, whih ws through joint nlysis etween the over rops nd soil depths evluted. The mens were ompred through the Tukey test of mens (p.5). These tests were rried out with the use of SISVAR softwre (Ferrreir, 21). Conlusion The over rops evluted in this reserh ffeted the exhngele mgnesium nd potssium, s well s the mgnesium nd potssium sturtion. The phosphorus ontent hnged in response to over rops, whih ws quite importnt to oserve tht this nutrient my inrese the ontent with doption of over rops in no-till system. These speies used in this reserh my e reommended to integrte rop rottion system with the possiility of inresing phosphorus vilility in soil. In Oxisol, s the se of this reserh site, the phosphorus ontent is the most limited nutrient in soil, the use of over rops tht improve its vilility is gret step to eome the no-till system sustinle. Aknowledgement The uthors re grteful to Universidde Federl d Grnde Dourdos (UFGD) for the ollortion of reserhers nd Brzilin Federl Ageny (Coordenção de Aperfeiçomento de Pessol de Nível Superior- CAPES) for the finnil support to the omplishment of this work. Referenes Adollhi L, Munkholm LJ (213) Tillge system nd over rop effets on soil qulity: I hemil, mehnil nd iologil properties. Soil Si So Am J. 78(1): Agede TM (21) Tillge nd fertilizer effets on some soil properties, lef nutrient onentrtions, growth nd sweet potto yield on n. Soil Till Res. 11(1): Andriole I, Prdo R de M (212) Plnts de oertur em pré-sfr e dução nitrogend n fertilidde do solo em diferentes mds, ultivdo om milho em sistem de plntio direto e onvenionl. Semin Cien Agr. 33(3): Bssegio D, Sntos RF, Seo D, Znão JLA, Wernke I, Srto MVM (215) Short-term effets of rop rottions on soil hemil properties under no-tillge ondition. Aust J Crop Si. 9(1): Clegri A, Tieher T, Hrgrove WL, Rlish R, Tessier D, Tourdonnet S, Guimrães MF, Sntos DR (213) Longterm effet of different soil mngement systems nd winter rops on soil idity nd vertil distriution of nutrients in Brzilin Oxisol. Soil Till Res. 133: Cntrutti RB, Brros NF, Mrtinez HEP, Novis RF (26) Avlição d fertilidde do solo e reomendção de fertilizntes. In: Novis RF, Venegs VHA, Brros NF, Fontes RLF, Cntrutti RB, Neves JCL, eds. Fertilidde do solo. 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