Intensive Olive Farms Contribute to Desertification in Spain, Experts Warn

Researchers caution that one-fifth of Spain is at risk of desertification. Poor agricultural and land-use practices paired with historic mismanagement are largely to blame.

By Paolo DeAndreis
Sep. 14, 2021 07:04 UTC

The specter of deser­ti­fi­ca­tion looms across some of Spain’s most prodi­gious agri­cul­tural regions.

According to the gov­ern­ment, Andalusia, the largest olive oil-pro­duc­ing region by a wide mar­gin and home to most of the world’s super-high-den­sity olive groves, is among the most at-risk ter­ri­to­ries.

Desertification is always caused by human over­ex­ploita­tion of a nat­ural resource with a slow renewal in dry­lands, such as ground­wa­ter or nat­ural pro­duc­tiv­ity.- Gabriel del Barrio, researcher, Arid Zones Experimental Station, CSIC

The tech­no­log­i­cal changes asso­ci­ated with the new devel­op­ments in olive agri­cul­ture raise some envi­ron­men­tal uncer­tain­ties,” Gabriel del Barrio, a researcher at the Arid Zones Experimental Station within Spain’s national agency for sci­en­tific research (CSIC) in Almeria, told Olive Oil Times.

See Also:One-Fifth of Italy at Risk of Desertification, Irrigation Experts Warn

Traditional groves are sim­i­lar to vir­gin forests in that they grow nat­u­rally in dry soil with deep roots. However, super-high-den­sity groves tend to have shal­low roots and are per­pet­u­ally wet due to con­tin­u­ous drip irri­ga­tion.

Furthermore, tra­di­tional orchards might include cen­turies-old trees, while high-den­sity groves (referred to as inten­sive groves in Spain) are usu­ally made up of trees that are only a few decades old. Finally, super-high-den­sity groves (super-inten­sive) include trees whose life expectancy does not exceed 14 or 16 years.

Spain is by far the largest olive oil pro­ducer in the world but still has the poten­tial to con­tinue rapidly increas­ing pro­duc­tion as a result of the pro­lif­er­a­tion of high-den­sity and super-high-den­sity groves, accord­ing to Juan Vilar, a strate­gic con­sul­tant for the olive sec­tor.

Spain has enough trees to achieve, as of right now, two mil­lion tons of olive oil pro­duc­tion,” he told Olive Oil Times in a July 2021 inter­view.

In the 2020/21 crop year, pro­duc­tion reached 1.4 mil­lion tons. Both the sheer quan­tity and high qual­ity of its olive oils make the coun­try one of the world’s most rel­e­vant olive oil exporters. The vast major­ity of this pro­duc­tion comes as a result of the country’s super-high-den­sity groves.

However, the impact of this type of pro­duc­tion on the ecosys­tem has yet to be fully under­stood, accord­ing to del Barrio.

The con­se­quences of these trans­for­ma­tions to the soil bio­log­i­cal sys­tems, includ­ing the par­a­sitic ones, and the ground-atmos­phere exchanges of water and energy, remain almost unex­plored,” del Barrio said. An asso­ci­ated issue is the high irri­ga­tion require­ment in areas that are nat­u­rally dry.”

In the report Approach to the Costs of Olive Growing,” recently cited by El Mundo news­pa­per, the Spanish Association of Olive Growing Municipalities (AEMO) reported that the tra­di­tional olive groves rep­re­sent 71 per­cent of all olive-ded­i­cated ter­ri­to­ries with a total of 2.5 mil­lion hectares. Of those, 49 per­cent are con­sid­ered mech­a­niz­able, while 22 per­cent have to be cared for by hand.

Yet, the costs to run and main­tain tra­di­tional groves in a mar­ket dom­i­nated by high-den­sity and super-high-den­sity groves are so high that landown­ers are in the process of aban­don­ing 130,000 hectares of groves, with another 500,000 hectares con­sid­ered at risk of aban­don­ment.

While har­vest­ing a tra­di­tional grove might cost between €0.20 and €0.25 per kilo­gram of olives, for super-high-den­sity groves that cost might be as low as €0.05 or €0.06, accord­ing to esti­mates from Almazaras de la Subbética, which El Mundo cited.

The researchers said that iden­ti­fy­ing the causes and effects of the soil trans­for­ma­tion are the first steps in under­stand­ing how socio-eco­nomic and envi­ron­men­tal fac­tors con­tribute to the cur­rent trend. Desertification is the cause, and land degra­da­tion is the effect.

According to Spanish sci­en­tists, 20 per­cent of the coun­try’s land is cur­rently degraded due to the cli­matic and social changes that pro­duced deser­ti­fi­ca­tion in the past.

This is his­tor­i­cal degra­da­tion asso­ci­ated, for exam­ple, with defor­esta­tion due to the min­ing indus­tries of the 19th cen­tury or to the fol­low­ing expro­pri­a­tion of land from the church at the end of the 19th cen­tury into the early 20th, land that was sub­se­quently auc­tioned for profit,” del Barrio said.


According to the CSIC researchers, this type of land­scape is some­what sta­ble and does not cre­ate envi­ron­men­tal issues, although it needs restora­tion.

A fur­ther 30 per­cent of the land is unpro­duc­tive with a low bio­mass, which could be con­sid­ered mild degra­da­tion,” del Barrio said.

When con­sid­er­ing the whole coun­try’s ter­ri­tory, only 30 per­cent of the land is not cur­rently under­go­ing deser­ti­fi­ca­tion or at risk of the phe­nom­e­non.

Desertification is always caused by human over­ex­ploita­tion of a nat­ural resource with a slow renewal in dry­lands, such as ground­wa­ter or nat­ural pro­duc­tiv­ity,” del Barrio said. Normally, it is trig­gered in a tem­po­ral win­dow oppor­tu­nity asso­ci­ated with a favor­able cli­matic oscil­la­tion, such as a rainy period, or a tech­no­log­i­cal devel­op­ment, for instance, a more effi­cient ground­wa­ter extrac­tion.”

In this sce­nario, the local pop­u­la­tion tunes its efforts and econ­omy to such an ephemeral period and becomes trapped when the exploited resource is com­pro­mised, either because the cli­mate fluc­tu­ates to the oppo­site end, or because the resource does not sup­port such extrac­tion rate,” del Barrio added. This is the essence of deser­ti­fi­ca­tion and is what causes soil degra­da­tion.”

Still, researchers found that only one per­cent of the land is under­go­ing active degra­da­tion, a pro­por­tion they say resem­bles what is to be found in many other areas of the world, such as north­east Brazil, China and the north­ern Maghreb, among oth­ers.

However, it is impor­tant to under­stand that the cor­re­spond­ing sites are being actively over­ex­ploited,” del Barrio said. They act as black holes in the sur­round­ing land­scape, to which they export envi­ron­men­tal dis­or­ders such as aquifer deple­tion, flash floods, seques­ter­ing of tra­di­tional man­age­ment and more.”

Parts of Levante, the Canary Islands, south­ern La Mancha, the Ebro Valley, parts of Extremadura and the Sea of Olives in Andalusia are all under­go­ing active deser­ti­fi­ca­tion.

Other regions, includ­ing Murcia and Huelva, are also on track to join the list if noth­ing changes.

Teresa Ribera, Spain’s min­is­ter for eco­log­i­cal tran­si­tion and the demo­graphic chal­lenge, told the Financial Times that Spain is the European Union coun­try at great­est risk of deser­ti­fi­ca­tion” and said the gov­ern­ment would announce a new strat­egy to com­bat the phe­nom­e­non in the com­ing months.

One of the rea­sons for Ribera’s stark assess­ment is that land degra­da­tion caused by deser­ti­fi­ca­tion is almost irre­versible on human time scales because those areas’ ecosys­tems have under­gone extreme sim­pli­fi­ca­tion and lack resilience to sig­nif­i­cant changes in the envi­ron­ment.

Researchers are work­ing to iden­tify those irre­versibil­ity thresh­olds,” which will enable farm­ers, sci­en­tists and politi­cians to take action before a tip­ping point is reached. Still, many other affected areas can be restored through refor­esta­tion or other pro­grams that pro­mote bio­di­ver­sity.

The chances of a site to remain degraded, recover or accept recov­ery, depend largely on its start­ing con­di­tion,” del Barrio said. This is why we think that maps of land con­di­tion, depict­ing all the states of eco­log­i­cal matu­rity and not only degraded states, are a great plan­ning tool to man­age the land­scape con­ser­va­tion and restora­tion.”

Therefore, the solu­tion is a care­ful mon­i­tor­ing approach,” he added. It can be done using remote sens­ing of land sur­face to assess the advance or retreat of land degra­da­tion, and many inter­na­tional ini­tia­tives are being suc­cess­ful in this line.”

In par­al­lel, socio-eco­nomic processes sub­stan­ti­at­ing deser­ti­fi­ca­tion can be, and are being, math­e­mat­i­cally mod­eled to explore long-term sus­tain­abil­ity and resilience under chang­ing sce­nar­ios,” del Barrio con­tin­ued.

According to the researchers, the chal­lenge is to link both approaches.

That means to for­mal­ize feed­backs between the past, the degraded land and the present, and the deser­ti­fi­ca­tion processes,” del Barrio said. Such feed­back is known, of course, but has to be coded into proper deci­sion sup­port sys­tems, and this is what keeps a great part of the sci­en­tific com­mu­nity occu­pied.”

Other options that might come into play for olive pro­duc­ers come from find­ing an appro­pri­ate equi­lib­rium between exten­sive and inten­sive man­age­ment, leav­ing unused land in between,” del Barrio said.

For exam­ple, green­houses in Almeria occupy a rel­a­tively small extent of land in rela­tion with their pro­duc­tion per­for­mance,” he added. While such land use brings about its own issues, and it is, in fact, one of the deser­ti­fi­ca­tion sce­nar­ios we have detected, con­cen­trat­ing pro­duc­tion in these areas leaves a large hin­ter­land in a nat­ural or semi-nat­ural state.”

Therefore, we should avoid bipo­lar­i­ties such as tra­di­tional-good ver­sus inten­sive-bad, which mis­lead to a sim­pli­fied eco­log­i­cal Manichaeism,” del Barrio con­cluded. Ours is a com­plex soci­ety, and solu­tions must be based on dynamic equi­lib­ria rather than on ideal sce­nar­ios.”

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