Land-Use Change Effects on Soil Quality in Montilla-Moriles DO, Southern Spain

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ff ´ antara, and B. Lozano-Garc Climate ´ antara ([email protected]) Sciences Sciences Dynamics Chemistry of the Past Solid Earth Solid Techniques Geoscientific Methods and and Physics Advances in Atmospheric Atmospheric Data Systems Geoscientific Geosciences Earth System Earth System Earth Measurement Instrumentation Hydrology and and Hydrology Ocean Science Ocean Biogeosciences The Cryosphere Natural Hazards EGU Journal Logos (RGB) and Earth System and Earth Model Development ect through photosynthesis and the C incorporation into carbohydrates ff ´ anchez et al., 2012). Crops capture CO ects (46 yr) of LUC (AC by OG and V) and to determine soil organic carbon ff n-Carrillo, L. Parras-Alc ı ´ ´ alez-S ected the thickness horizon, texture, bulk density, pH, organic matter, organic carbon, ff This discussion paper is/has been under review for the journal Solid Earth (SE). Please refer to the corresponding final paper in SE if available. crobial decomposition processes (Johnsonthe et best al., tools for 2007). climate Soil change management mitigation is and one adaptation of (Lal et al., 2011). Several 1 Introduction The soils playsphere a because crucial theythey role can can in either actachieve emit influencing this as e large the a quantities(Gonz carbon store of (C) for CO contenttosynthesis C by of (Smith converting the C et forms atmo- al., associated with 2000). soil Agriculture organic and matter (SOM) forestry for can mi- SOC stock (52.7 % and(42.6 64.9 % % and to 38.1 V % to and Vwas OG and opposite; respectively) OG, 46 and respectively). With years the respect after loss toratio LUC of the (in improved soil the V the quality, TN the and soil e stock OG) quality, increasing of the SOC, stratification TN and C:N ratio. (SOC), total nitrogen (TN), C:N ratioin and Montilla-Moriles their stratification denomination across of thean origin soil area entire (DO), under profile, in semiarid Calcic-Chromic Mediterraneanof conditions. Luvisols studying The (LVcc/cr), the experimental design LUCfarmed consisted in on 1965, one but farma OG between and 1965 V andtotal were 2011. nitrogen farmed and Originally, up C:N onlySOC to ratio. AC and now The was TN (2011). LUC had stocks. This a The LUC negative conversion principally impact from in AC the to soil, V a and OG involved the loss of the The agricultural Mediterranean areaslast are few dedicated decades, to agrove cultivations arable significant (OG) and crops number vineyards (V). (AC), of Along-term but field AC e has study in was a conducted the to land determine the use change (LUC) to olive Abstract Published by Copernicus Publications on behalf of the European Geosciences Union. Department of Agricultural Chemistry andof Soil International Science, Excellence Faculty – of ceiA3, Science, University Agrifood of Campus Cordoba,Received: 14071 27 Cordoba, December Spain 2012 – Accepted: 8Correspondence February to: 2013 L. – Parras-Alc Published: 22 February 2013 Land-use change e Solid Earth Discuss., 5, 163–187,www.solid-earth-discuss.net/5/163/2013/ 2013 doi:10.5194/sed-5-163-2013 © Author(s) 2013. CC Attribution 3.0 License. Montilla-Moriles DO, Southern Spain M. Mart 5 20 25 15 10 Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | ` a ), which is a weak 1 − ´ antara, 2013) to improving ¨ uneberg et al., 2010). Some 10 g kg ´ ∼ agy and Jackson, 2000). In the concentrations. 2 ´ edraogo et al., 2006; Yamashita et al., a and Parras-Alc ı ´ 166 165 ect of LUC from AC to OG and V on SOC and ff nez et al., 2003). ı ´ ´ ected by LUC for long-term in conventional tillage. andez et al., 2013) and the addition of organic residues ff ´ e et al., 2000). ˆ ot a et al., 2011; Lozano-Garc ı ´ Very few reports have compared the e Soil depth has a decisive influence on SOC stocks (Gr The concept of using the stratification ratio (SR) as a soil quality indicator is based on Regional-scale information about C stocks and the relationship between C reser- The soil C:N ratio is a soil fertility indicator due to the close relationship between SOC Land use change (LUC) is considered the second greatest cause of C emissions af- Carbon sequestration is defined as any increase in the C content of soils after a (LVcc/cr) (FAO, 2006) in AC a last few decades, a significant numbertivations of arable (OG) crops or (AC) have vineyards LUCLUC to (V) has olive in grove been cul- motivated Montilla-Moriles by Denomination subsidies of and better Origin olive (DO). oilTN This and storages wine even prices. on soilobjectives quality of for this long-term work in arevertical soil (i) entire distribution profiles. to of In determine SOC this theanalyze (entire context, the SOC soil the accumulation content profile and in SR by of the horizons, SOC, soil; non-section TN (ii) and control); C:N to (iii) ratio study in to its Calcic-Chromic Luvisols in temperate climates large amounts30 cm of deep. SOC This may is be essentialhorizon, in stored contributing LUC in to because subsoil the SOC horizons can subsoiltion be below C is transported storage one to (Lorenz of a and the deeperwith features Lal, soil the of 2005). relationships the Vertical with organic distribu- climate C and store vegetation that (Jobb is not clearly understood together undisturbed soil with highrelated soil to quality rate of and the amount surface of SOC layer. The sequestration (Franzluebbers, increase 2002). authors of have evaluated SR the SOC can content be in50 soil cm), surface and (restricted few to studies the have upper includedtian, 15–30 a or deeper 2002), section although of soil vertical(VandenBygaart, cover (Conant 2006). processes and have Sombrero Paus- and a Benitopare significant (2010) SOC impact noted storage that on complete to SOC profile evaluate and variability is com- necessary. According to Lorenz and Lal (2005) 2006), vegetation types (Diekowmanagement et practices (C al., 2005; Puget and Lal,the 2005), influence and of agricultural the SOCconservation surface (Franzluebbers, level 2002). in High erosion control, SR water of infiltration SOC and and nutrient TN pools reflect relatively climate (Miller et al., 2004), soil conditions (Ou and total nitrogen (TN). The soil C:N ratio is often influenced by many factors such as and/or tillage has a significant impactal., on 2005; this Van large Hemelryck pool et of al., SOC 2011). (Lal, 2003; Van Oostvoirs and et edaphic factors coulduating be relevant gains to and determine LUC lossesand that of management is SOC of are interest (Novara highly in etranean eval- influential climate, al., in characterized 2012). the by Inand C a Spanish degradable variability, structure low soils, mainly (Acosta-Mart SOM climate, in content use the ( dry Mediter- et al., 2010). Long-term(SOC) experimental is studies have highly confirmed sensitive to thator LUC soil decrease (Smith, organic in 2008). carbon soil Thus,tices, carbon even may a content result relatively due small in toatmosphere increase a changes (Houghton, significant in 2003). land net Recently, it use exchange has or of been management shown C prac- that between soil the erosion soil by C water pool and the tant ecosystem services becausesive of its and role conventional in tillagebon climate (SOC), regulation (CT) thus (IPCC, may inducing 2007).(Melero cause an Inten- et increase enormous al., in 2009). losses soil erosion of and soil a organic breakageter of car- fuel soil consumption (Watson structure et al.,soil 2000). loss, LUC has leading contributed to to soileven a degradation more and decrease intensely in in soil the C Mediterranean storage areas worldwide during (Eaton the et last al., few 2008), decades and (Cerd striction on tillage (Corral-Fern (Lozano-Garc soil properties and diminishing atmospheric CO change in land management (Powlson et al., 2011) and is one of the most impor- authors have proposed introducing soil management techniques that combine a re- 5 5 25 15 20 10 25 20 10 15 Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | ) – 1 0 − 38 erent ◦ ff ´ enez variety. ) was calculated 1 − ). The TN stock (Mg ha 3 0.1 (1) − × %) is the fractional percentage (%) of 2mm C and an average annual rainfall of δ ◦ 2 mm − δ (1 × 168 167 d × C to 37.8 ◦ 2 BD − × 0.05 were considered statistically significant. (6 %) to remove organic matter. The fraction of particles with p < 2 erences in the variables between land use practices was tested O ff 2 W, 432 m a.s.l.). Montilla is the first production center of Montilla- 0 SOCconcentration erences of –31 ff 0 = 45 is the thickness of the soil layer (cm), ◦ d N; 4 0 The SRs were calculated from SOC, TN and the C:N ratio data following Franzlueb- The statistical analysis was performed using SPSS 13.0 for Windows. The statistical An unirrigated farm (100 ha) of AC cultivated under conventional tillage (CT) was The parent material is Triassic marl mainly composed by clays, gypsum and salts. The Montilla-Moriles DO is characterized by cold winters and warm, dry summers 2 mm gravel in the soil, and BD is the bulk density (Mg m 2 mm were classified according to USDA standards (2004). Soil bulk density was soil type. Di was also calculated. bers (2002). The SRsame is property defined at a asBt, lower a [SR2] depth. soil for In Ap/Bt-B-Ck, this property [SR3] study, on for we Ap/C-Bt-C the defined and four soil [SR4] SRs for surfacesignificance ([SR1] Ap/C2-C-Ck). of divided for the Ap/Ap2- by di the using an Anderson-Darling test at each horizon or a combination of horizons for each for each horizon according to Wang and Dalal (2006)SOCstock as follows: where > a diameter greater< than 2 mm wasmeasured determined by the by core wet10.0 method cm sieving. (Blake deep Particles core. and hartge, The measuring son 1986) distribution pipette of using method soil a (USDA, particle 2004). 3.0 size cm SOCmate was were diameter according determined analyzed and using by to wet the thethe oxidation Robin- with Kjeldahl Walkley dichro- method and (Bremner, 1996). BlackSOC The system concentration soil by C:N (1934). the ratio TN TN was concentration. calculated was The by determined SOC dividing stock the using (Mg ha The soil samples werewas measured air-dried, in ground an aqueous andand soil sieved Carballas, extract through in 1976). deionized Prior awere water to 2-mm (1:2.5 treated soil:water) determining with sieve. (Guitian H Soil the particle pH size distribution, the samples 2.2 Soil sampling and analytical methods selected for study in2006). In 1965. 1966, the The studyuses soil farm (AC, (100 was OG ha) and was a divided VAC Calcic-Chromic into respectively). (AC1) three The Luvisol and plots preliminary the (LV with analyses second cc-cr) three2011, were analyses di 22 realized (FAO, were samples in realized were 1965 in collected for all (7 2011 cases for for (AC1, AC2, AC2, AC OG 5 (AC2), andthe for OG V) V land and were and use collected V. 10 class In soil for and entire OG) Table profiles. 2 (Figs. Table 1 summarize 1 summarizes the and principal 2). soil In properties for the study. of limestone, which combines permeabilityis with essential high for water lands retention. with This latter frequent feature dry spells. with temperatures ranging602.7 from mm. The moistureto regime altitude and is location. dry Mediterranean with continental features due Moriles wines. This DO produced wines with the grapes ofThe the relief Pedro Xim is smoothare with Luvisol slopes (LV) and rangingalbarizas”, Cambisol from although (CM), 3 there % denominated2006). to are in These 8 Fluvisol soils the %. correspond (FL), study The tosubperiod), Regosol most region the which upper are abundant “alberos (RG) limit characterized soils and and by oflimestone) the the typical Vertisol presence Pliocene of (VR) of the period Guadalquivir white (Andaluciense (FAO, basin. marls These (argyle-containing are soft soils owing to the presence 2.1 Site description and experimental design The study area comprises 33607 ha29 located in Montilla-Moriles D.O., Cordoba (37 2 Material and methods 5 5 25 15 20 10 25 15 20 10 Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | 0.05) in erences ´ alez and ff p < erences ( ff ´ a and Lal, 2009; Wright et 170 169 ) than that estimated by Don et al. (2007), who 1 − for soils with cereal crops in Spain, which must be caused by the 1 − ´ as (2004) found that the formation of OM and mineral aggregates diminishes in TN and the C:N ratio tended to decrease with depth with the exception of AC2. According to the study of Hernanz et al. (2009) on rainfed crops of Mediterranean These soils are characterized by low OM concentrations in depth, especially in With respect to the soil thickness, there were no significant di ´ a et al. (2001) observed an increase in the soil C:N ratio with deep (AC2), which and Lal, 2005). Additionally,(Xu a et residue al., retention 2011)et can with al., increase a 2006). the lower decomposition Under proportiondistributed degree AC2 of with and the depths SOC higher incorporation up C:Nal., to of 2007). ratio 20 By residues cm, (Yamashita contrast, into under or AC1 more theConsequently, and the V than soil soil the 20 C:N input can cm of ratio be (S residues mayin is be uniformly the restricted stratified to upper to the show soil topsoil. asoil profile. declining horizons, The trend especially C:N with in ratio depths Vand in (12.23:1) separation the and rates. OG surface Lal (9.44:1), soil et thus was al. indicating (1995) higher high indicate than resolution that in C:N the ratios lower are low during resolution may be attributed to high(Diekow C:N et soluble al., organic compounds 2005).clay leaching content For into with OG, deeper depth layers thisdecomposed (Table OM decrease 2). with may Higher a lower beIn clay C:N the content a ratio case is (Puget result and of often of Lal AC1 associated the 2005; and with Yamashita increased et V, more al., crop soil 2006). residues could favour a higher soil C:N ratio (Puget of the OM andtrary, the soils absence with the of harvest coverage ofand residues trees Kandji, after show 2003); periods an increase we offound in drought. obtained in C On similar and AC1 the nitrogen results was (N) con- established greater in (Albretch 10 (11.1 topsoil, g g kg kg in Vaccumulation and of litter OG. and The dead SOC roots we in the topsoil. S In all cases (AC1,exception of V AC2 caused and by OG), the high the OM SOC concentration in concentrationsemiarid Bt regions; decreased (Table 2). the in soil depth presents with a low the OC content owing to the high mineralization 3.2 Soil organic carbon (SOC), Total Nitrogen (TN) and C:N ratio V and OG;Cand this can bethe explained surface horizons by of sandy theexplain soils, the soil thus low favoring textures OM high concentrations levels (sandy of atdition, transformed greater Gallardo soils). OM, et depths al. in which Gonz (2000) the explains soilsemiarid that studied Mediterranean the (Table conditions, low 2). OM which In values are ad- are accentuated explained partly in by Europe’s the southern soils. steepness, length, topographic curvatureand and Austin relative (1993) position. obtained Inal. similar this (2005) results line, in in McKenzie and Lesvos-Greece Australian 1996 for justified soils. this LUC By thickness reduction (AC(heavy contrast, associated machinery) to Bakker with and new et V mechanized water equipment erosion. andthe These thickness pastures reduction causes in to could the be OG) studied other soils. between reasons 1956 to justify these soils is a(caused high by clay clay content migration)suitable (Table in 2). for the a Luvisols broad subsoil are variety (Btolives well-developed of and fertile horizon) uses vineyards typically soils compared (Zdruli Mediterranean that et to such are al., as the 2011). cereals, topsoil fruit trees, time (46 yr) for the sameOG land the use soil (AC1 and thickness AC2), decreased, however,V the ranging and LUC from OG from 240 cm respectively AC1 (Table to in 2). V AC1 This and to thickness reduction 182 cm could and be caused 176 cm by in the slope 3.1 Soil properties The studied soil;in a some LVcc/cr physical (FAO, and 2006) chemical was parameters characterized with depth. by The exhibited principal di characteristic of 3 Results and discussion 5 5 25 15 20 10 25 15 20 10 Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | ) 1 1 − − ect and ff 1 − ´ alez and erence of ff 35 Mg ha ˜ noz-Rojas et ects of deep- ± ff and 39.9 Mg ha 1 − ord (2002) reported an ff in AC. This di ), V (157.2 1 1 − ˜ noz-Rojas et al. (2012a) for − , respectively. Gonz 1 − , 42.5 Mg ha 1 erences between SOC stocks for − ff 32 Mg ha ± to 48.9 Mg ha 172 171 guez-Murillo, 2001) and the SOC stock for ı ´ 1 − ected by LUC; the highest SOC was found under AC1 ff ) (Fig. 3). These di 1 − ´ e et al., 2000) state that the N mineralization decreases ˆ ot ect that has also been shown by Nair et al. (2009). Both authors ff ˜ noz-Rojas et al. (2012b) used two or three horizons by profile – ective in C sequestration than other land uses. ) followed by AC2 (229.0 ff ect can be observed in AC1 and OG, which increased the clay 1 ff 21 Mg ha − ± for LV and soil uses is 50.5 Mg ha 1 for LV in arable crop and permanent crops respectively (Mu − ect of LUC on SOC stock, TN and C:N ratio 1 ff − ected the SOC stock that was reduced 31.2 % and the LUC from AC1 to V ff 28 Mg ha a (Map of soil organic carbon content in Andalusia) are 53.2 Mg ha ı ´ ± ´ as (2004) in clayey soils found values near 54 Mg ha The loss of SOC stock was caused by tillage (Table 1), AC1 had minimum tillage, In our study, TN concentrations are elevated in areas where the SOC is high, show- We can be observed that the LUC (AC1 to V and OG) and tillage (AC1 to AC2), with higher biomass production of plantations. As a result, the soil was always covered alization decreases. 3.4 The e A fundamental issue hasto been AC2 to a analyze theand LUC OG were influence. reduced Thefor 52.7 change LUC % from from and AC AC1 64.9 %,increase to of respectively V 18 (Fig. find % on 3). an SOC increase Novara stock et of for al. 105 LUC %. from (2012) Guo AC and to plantation. Gi and could indicate2010). a Some positive studies relationshipwhen (C the between clay amount clay increases and increased the when nitrogen soil. the We (Sakin obtained amount similarclay of et results amounts clay in increase al., increased. LV as in McLauchlan TN soil, (2006) de- aggregate explained amounts that increase when and the potential N miner- 2004). Moreover, Vallejo et al.pastures, which (2003) is an indicates e thatalso the indicate SOC that the stock potential isthe for C greater roots sequestration in transfer in large crop grass systemsin amounts increases the of because underground C C in content,systems the which are soil accumulates more over slowly e time, and thus contribute indicating to that the these increase ing a positive C:N relation (Fig. 3). According to this, clay decreases SOC oxidation C in the formrooting crops of (Shrestha dissolved et organicLUC al., (51-yr C, 2004). period) On soil between the fauna 1956permanent contrary, and activity, crops) Mu 2007 found and/or in an the Andalusia increasethat (conversion of e of SOC agricultural arable for management crop LV (14 in to %), caused permanent by crops the has limited on e SOC sequestration (Smith, (Bt and Bt/C horizons) in AC1 and AC2, which may be due to the translocation of in the soil.content This with e respect to AC2 and V. By contrast, SOC stored was higher in the subsoil in V wefrom found AC higher to SOC Vmixing in obtained similar of the results the topsoil. and upperAC1 In explained soil that and layers this this during AC2 line, trend soil variedCand Novara may tillage. from be et SOC 39.7 due Mg stock al. ha to inSOC (2012) the the stock for surface is LUC horizon caused in (Table by 2). the According texture toSOC because Burke our stock et soils in al. were clayey (1989) less soils clayey and are and Leifeld caused sandier et by al. the (2005), stabilization high mechanisms values of of the clays soil thickness (we usedMurillo (2001) soil and complete Mu profilenot entire – profile). four or five horizons andreduced Rodriguez- the total SOCwithin stock the in soil profile, the with long higher term values in (46 Bt yr) horizons (Fig. for 3). AC1, AC2 The and SOC OG, however, stored varies is 66.0 Mg ha for AC, VAndaluc and OG57.3 respectively Mg ha (Rodr al., 2012). The SOC stock was(332.6 a and OG (116.7 soil groups in Peninsular Spain and Andalusia and the study soils are caused by and 15:1, with an average of 12:1. 3.3 Soil Organic Carbon (SOC) andThe Total SOC Nitrogen stock (TN) for stocks soil groups in Peninsular Spain (FAO soil map of peninsular Spain) and separation times. Brady and Weil (2008) show that C:N ratios varies between 8:1 5 5 25 15 20 10 25 15 20 10 Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | ´ a and Lal, erences in SR, in a ff ect can be explained erent tillage. ff ff erences with respect to ff 174 173 ect in the LUC and tillage system on the carbon accumulation in the ff The higher soil quality was OG and V, compared to AC1 and A2 was probably due The SR of TN showed a similar trend in the SR of SOC. The SR of C:N ratio in- Franzluebbers and Arshad (1996) and Melero et al. (2009) suggest that minimum The C:N ratio was higher under AC1 than under AC2, V andIn OG (Fig. OG 3). and This V, SOC is storage in at surface depth (Ap horizon) was high than in the rest decomposition degree of SOCsuggests decreases little toward e the surfacesoil. (Lou Balesdent and et Balabane al., (1996)Geauga 2012). do farm This not (Ohio). find In anyface AC2, significant horizons V di to and a OG deeperprofile had horizon, under ensured these which the systems. suggested supply an of accumulation OM of from carbon in theto the sur- the presence ofof a herb a layer herb and layer, the in low both herbicide protecting applications. soil The from important the role erosion process (Novara et al., 2011) creased in depth, insoil AC1 use. and This OG, canputs be but leading explained had by a no a higherinput significant higher soil di could contribution C:N have of been ratioage, residue concentrated so (Puget relative to the on and root soil the Lal, in- C:N surface 2005). ratio due Under was to AC1, stratified. straw the This soil slight residue surface change cover- in C:N ratio suggests the LUC improved soil qualitychemical because properties and LUC the caused soil biotic alterationssoils, community (Caravaca in the et al., the SR 2002). soil’s of For2002). degraded physical SOC Other and studies is have low shown that and(Franzluebbers, SR 2002; occasionally ranges from reaches Franzluebbers 1.1 et a to2009). 1.9 al., value Higher for of 2007; conventional SR tillage 2.0 Hernanz of (Franzluebbers, to et SOC straw is al., soil a 2009; surface consequence coverage S and of root the distribution accumulation change. of surface SOC due In all cases,caused the by SR the of lowBt, SOC SOC caused concentration increased by in in the Ap2/B heavySR3 deep (transitional machinery). and horizon with The SR4] between SR the increased Ap of exception due and SOC of to for surface LUC AC2 to in (Fig. depth all 4), [SR1, situations SR2, (AC2, V and OG) (Fig. 4). The 3.5 Stratification of SOC, TN and the C:N ratio reduced SOC stock. crop biomass and ininverse turn (SOC residue increased return. in Bt Withby with respect soil respect to texture to Bt Ap (sandy horizon,surface, horizon). soils) This which this and e may relation tillage, be was because,into attributed native deeper to SOC soluble layers, can organic increasing beDiekow compounds et reduced the al. that on soil (2005). can the aggregates. be A leaching similar resulttillage was can increase obtained SOC by cause under in longer experimental AC1 duration. increased We SOC confirmed this stock be- and the LUC and tillage for long-term (40 yr) of the profileand (Fig. Lal 3), (2008), West argued that andto SOC tillage Post stock and on (2002), surface in Pugetdecomposition. horizon turn is and However, increasing greater AC1 Lal than the can (2005), in physical increase deep Blanco-Canqui protection due C of inputs native into SOC surface from soil microbial by enhancing tinuous impoverishment in theunsuitable OM chemical content properties. causing low Moscatelliin productivity, et cultivated which soils al. derived could (2007) in physical be indicated protection due that of to theconsequence soil the of SOC from tillage. OM loss erosion reduced and input, the as well increasedline as decomposition with to the rate results the as of reduced be Blanco-Canqui a explained and by Lal the (2008) higher and contribution Lou of et residue al. input (2012), under which di may The lowest SOC stockresult was was in obtained OG by thatLUC Rodriguez-Murillo reduced of (2001) 64.9 % bushland and with to Padilla respectof et OG to SOC al. and AC1. stock (2010), the A from the secondresult similar AC1 first of to for for the AC2, LUC vegetation V losses of and and shrubland an OG, to unsustainable can soil OG. management be This resulting explained in reduction by con- a degraded process with vegetation, increasing OM stability, which is corroborated by Novara et al. (2012). 5 5 25 15 20 10 25 15 20 10 Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | ects of ´ ff a for his a, B.: Stratification ratio of soil or- ı ´ ect in the soil, increasing the SR (in V and ff 176 175 ´ antara, L., and Lozano-Garc az, A., Hooke, J., and Montanarella, L.: Soil erosion and degra- ı ´ I would like to express my very great appreciation to A. Cerd ects on soil organic matter content in US grassland soils, Soil Sci. Soc. Am. J., ff nez, V., Klose, S., and Zobeck, T. M.: Enzime activities in semiarid soils under ı ´ ´ andez, R., Parras-Alc ` a, A., Lavee, H., Romero-D dation in Mediterranean type ecosystems, Preface. Land Degrad. Dev., 21,ecosystems, 71–74, Glob. 2010. Biogeochem. 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Plant Nut., 166, In general, the LUC reduces the SOC and TN concentrations and by contrast in- The reduction of SOC by LUC, can be explained by a degraded process (due to Conant, R. T. and Paustian, K.: PotentialCorral-Fern soil carbon sequestration in overgrazed grassland Cerd Caravaca, F., Masciandaro, G., and Ceccanti, B.: Land use in relation to chemical and biochem- Burke, I., Yonker, C., Parton, W., Cole, C., Flach, K., and Schimel, D.: Texture, climate, and Bremner, J. M.: Total nitrogen, in: Methods of Soil Analysis: Chemical Methods, Soil Sci. Soc. Brady, C. and Weil R. R.: The nature and properties of soils. 14th ed. Pearson Prentice Hall, Blake, G. R. and Hartge, K. H.: Bulk density, in: Methods of Soil Analysis: Part 1, Physical and Blanco-Canqui, H. and Lal, R.: No-tillage and soil-profile carbon sequestration: an on farm Bakker, M. 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The LUC has a negative impactstored in varies the soil, along reducing themixing the SOC of profile, and the with TN upper stocks. highercation The soil SOC values of layers C in during in soil thedeep-rooting the tillage) Ap crops). form and horizon TN of Bt concentrations dissolved (caused horizonsshowing were organic by (due a high C, positive to the soil in C:N the fauna areas relation. translo- activity, where and/or the the SOC e wasvegetation high, losses and unsustainable soilpoverishment management, in which the result SOM content, in causing progressive low im- productivity, which derived in unsuitable of the OG and V. 4 Conclusions and contributing to SOM content, might explain the similarity among the characteristics 5 5 30 25 20 15 10 15 20 10 Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | ´ on de ´ alez, O., erent?, Glob. ff and soil losses in southern ects of agricultural manage- ¨ ff ff ogel-Knabner, I.: Soil C and N ects of olive mill by-products on soil ´ ff andez-Ales, R.: Soil Nitrogen hetero- ´ alisis de Suelos, Edit. 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7.97 9.44 12.23 12.47 1 − TN 5, 7, 5, 2.81 3.84 3.55 3.99 65 (AC1), after g kg = 1 − conversion n 0.06 13.47 0.02 12.96 0.17 12.09 0.09 12.07 0.06 0.03 7.32 0.02 7.86 0.05 9.03 0.06 7.71 0.05 0.03 9.68 0.01 8.00 0.06 12.42 0.03 8.52 0.06 0.03 7.47 0.04 6.00 0.07 6.98 0.06 6.54 0.02 ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ±

1.07 0.89 1.53 1.03 SD ( ± 1 − 44.9 31.8 29.5 28.8 SOC g kg g kg 1 by by land use −

0.6 0.67 0.5 0.53 1.2 0.6 0.86 0.3 0.98 0.5 0.62 0.5 0.35 0.9 0.5 0.63 0.2 0.55 0.4 0.33 0.3 0.27 1.1 0.6 0.87 0.5 0.85 0.6 0.53 0.4 0.52 1.2 0.5 0.75 0.2 0.71 ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± g kg

). affect 1 − 0.6 4.1 0.4 2.3 2.4 10.1 1.7 6.5 0.2 5.1 0.6 3.7 0.3 3.4 1.1 11.1 1.0 10.1 0.7 9.2 0.6 8.1 0.8 6.4 2.4 9.5 1.7 6.3 0.8 7.7 1.6 5.6 0.9 2.7 1.2 12.6 0.6 6.1 0.3 4.4 ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± O g kg thickness 2 0.3 19.0 0.7 17.4 0.4 15.8 0.8 13.8 0.3 11.0 0.9 16.2 0.4 10.7 0.6 13.1 0.4 9.5 0.3 4.6 0.7 21.6 0.2 10.5 0.6 7.5 0.8 7.0 0.1 3.9 0.5 17.3 0.7 11.1 0.6 8.7 0.1 6.3 0.1 5.7

± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ect by land use conversion (LUC) to ﬀ soil 3 − 0.21 7.1 0.12 7.2 0.31 7.7 0.21 7.6 0.34 7.7 0.16 7.6 0.34 7.5 0.11 7.6 0.36 7.9 0.48 7.8 0.31 8.1 0.26 8.1 0.21 8.3 0.14 8.3 0.22 8.4 0.24 7.9 0.32 7.9 0.12 8.0 0.17 8.0 0.21 8.1 ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± Mg m 2.1 1.42 3.1 1.47 2.3 1.51 3.9 1.51 3.4 1.51 1.2 1.25 2.5 1.39 6.3 1.29 6.1 1.31 3.4 1.33 2.9 1.43 2.1 1.53 3.1 1.58 6.2 1.69 3.9 1.74 3.2 1.43 2.8 1.45 4.6 1.43 3.7 1.47 1.6 1.57 184 183 ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± 1.8 56.9 3.4 62.1 2.7 52.8 4.1 43.9 3.2 36.5 3.4 25.6 1.7 39.3 4.2 36.6 4.8 27.9 2.6 21.0 3.1 14.3 2.9 24.0 3.9 19.4 4.5 22.8 5.7 27.8 6.7 38.5 2.5 33.2 4.6 45.3 5.4 46.5 3.8 38.1 ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± 2.2 13.3 2.8 10.8 2.1 25.7 3.2 30.7 5.3 33.6 3.1 41.6 2.7 32.2 4.3 28.3 2.6 42.2 9.8 33.6 3.4 46.4 2.7 34.0 5.1 40.1 4.8 33.8 3.7 41.6 2.4 14.9 3.7 34.7 6.2 26.4 5.4 31.3 3.6 32.8 ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± 1.5 35.1 0.8 29.9 0.9 45.4 1.1 39.3 0.9 42.0 0.7 30.6 0.3 29.4 1.1 29.9 0.9 32.8 0.5 28.5 0.8* 29.8 0.4* 27.1 0.5* 21.5 0.3* 25.4 0.6* 40.5 0.3* 43.4 0.5* 32.1 0.4* 30.1 0.3* 22.2 0.4* 29.1 ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± Soil entire profiles. AC1 (arable crop in 1965), . 1 3.1 1.5 4.23.3 0.9 1.3 6.3 1.2 4.1 2.4 2.2 3.3 3.5 3.1 3.6 2.4 6.2 2.3 2.1 2.9 1.8 3.3 2.9 3.0 6.5 1.8 2.4 1.4 3.2 2.3 3.9 2.3 1.2 1.5 9.4 0.7 2.6 1.1 4.2 1.2 ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ±

Figure Figure to AC2 V crop), (vineyard) (arable and OG (olive The groves). was LUC in 19 V AC2, and (Numbers are OG. the 41 years, cm cm % % % % density H Horizon type. *No signiﬁcant data for Stratiﬁcation Ratio (SR).

Basic physical and chemical properties for Calcic/Chromic Luvisol in Arable land 1 2 3 4 5 = Soil entire proﬁles. AC1 (arable crop in 1965), a Ap 0–25 25 BtB/C 80–115 25–80 35 55 C1 115–185 70 C2 185–240 55 Ap 0–36 36 Ap2/B 36–74 38 Bt 74–113 39 Bt/C 113–218 105 C/Ck 218–256 38 Ap 0–35 35 Bt 35–72 37 B/Ck 72–115 43 C1 115–150 35 C2k 150–182 32 Ap 0–27 27 Ap/Bt 27-37 10 Bt1 37–85 48 Bt2/BC 85–109 24 C 109–176 67 5 5 7 10 = = = = n AC1 Soil Hor. Depth Thickness Gravel Sand Silt Clay Bulk pH OM SOC Total TN Total C/N n AC2 n V OG n AC2 (arable crop), V (vineyard)41 yr, and AC2, OG V (olive and groves). OG. The (Numbers are LUC soil was thickness). in 1965 (AC1), after the Fig. 1. 10). Hor. Table 2. (wheat and barley annualArable rotation), crop 2006, Vineyard V: and Vineyard Olive 2006, OG: groves. Olive AC1: groves Arable 2006. crop Data are 1965, means AC2: Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper |

22 news

). 5,7,5,10). =

n 5, 7, 5, 10 SD ( ± ± SD (n = = ± SD (n

means AC2 OG AC2) Arable crop, heavy machinery . (OG) Olive groves. 186 185 Data are Data are

modern (V) Vineyard

Moriles D.O. (AC1) Arable crop, systems using animal power (plow with -

Depth Depth distribution of SOC stock and TN stock under arable crop (AC1), arable crop 1

V AC Depth distribution of SOC stock and TN stock under arable crop (AC1), arable crop Montilla-Moriles DO (AC1) Arable crop, systems using animal power (plow with mules) Figure Figure 3. (OG). and Vineyard (V) Olive groves (AC2),

2 3 4 5 1

Figure 2. Montilla mules) with lightweight reversible plows. ( equipment. mechanized

Fig. 3. (AC2), Vineyard (V) and Olive groves (OG). Data are means Fig. 2. with lightweight reversibleequipment. plows. (V) (AC2) Vineyard modern. Arable (OG) crop, Olive groves. heavy machinery – news mechanized

9 3 4 5 6 7 8 2 1 13 14 15 16 10 11 12 Discussion Paper | Discussion Paper | Discussion Paper | Discussion Paper |

24 187

). 5, 7, 5, 10 ± SD (n = = ± SD (n

5,7,5,10). = Stratiﬁcation ratios (SR) of SOC concentrations, TN concentrations and C:N ratios under

Figure Figure 4. Stratification ratios (SR) of SOC concentrations, TN concentrations and C:N ratios under arable crop (AC1), arable crop (AC2), Vineyard (V) and Olive groves (OG). Data are means n

1 2 3 4 5 SD ( arable crop (AC1), arable± crop (AC2), Vineyard (V) and Olive groves (OG). Data are means Fig. 4.