New Tool Measures Soil-Atmosphere Interactions to Optimize Farming Practices

Researchers from Spain and Iraq have designed a new heat pulse probe to mea­sure the ther­mal con­duc­tiv­ity of the soil.

Normally, tak­ing these mea­sure­ments is com­plex and requires a lot of time and work. However, the sci­en­tists said the new probe is a ​“low-cost and easy-to-use instru­ment” that will help other researchers and agron­o­mists bet­ter under­stand the energy and mass exchanges between the soil and atmos­phere.

Most of these inter­ac­tions take place in the sur­face layer of soil and are sig­nif­i­cantly impacted by tillage prac­tices, fer­til­izer appli­ca­tion and micro­bial bio­di­ver­sity. Soil depth above under­ly­ing bedrock and soil type also play an impor­tant role.

The new probe includes a sam­pling sys­tem, mea­sure­ment cham­ber and elec­tronic con­trol sys­tem, allow­ing exper­i­ments to be car­ried out in the field in a range of con­di­tions. In addi­tion, the researchers said all the mate­ri­als used in its con­struc­tion are afford­able and com­mer­cially avail­able.

Most soil stud­ies are done by extrap­o­lat­ing raw soil data from exist­ing sur­veys. Other meth­ods to mea­sure soil ther­mal con­duc­tiv­ity in situ require spe­cific train­ing for oper­a­tors and sig­nif­i­cant amounts of elec­tric­ity. Additionally, their accu­racy is lim­ited by tem­per­a­ture range and soil water con­tent.

The researchers from the University of Granada in Spain and the uni­ver­si­ties of Wasit and Baghdad in Iraq believe that a bet­ter under­stand­ing of soil-atmos­phere inter­ac­tions, which are crit­i­cally impor­tant to life on Earth, is nec­es­sary as offi­cials seek to mit­i­gate the sub­stan­tial impacts of cli­mate change on agri­cul­ture.

They hope to estab­lish a base­line under­stand­ing quickly, so they may later study how cli­mate change affects soil-atmos­phere inter­ac­tions.

The researchers believe a bet­ter under­stand­ing of these inter­ac­tions will help farm­ers make more sus­tain­able deci­sions about when they till and how they apply fer­til­izer or mulch.

For exam­ple, ​“we have found that con­ven­tional tillage increases the tem­per­a­ture flux in the soil com­pared to no tillage, mainly due to the decrease in the bulk den­sity of the soil, that is, the increase in the porous sys­tem,” said Andrés Caballero Calvo, a geog­ra­phy pro­fes­sor at the University of Granada.

Researchers from Spain’s Experimental Station of Arid Zones pre­vi­ously said the ways in which cli­mate change is trans­form­ing how plants and soil inter­act is one of the less-dis­cussed but more dis­rup­tive impacts of cli­mate change on agri­cul­ture that deserves more atten­tion.

The researchers work­ing on the new heat pulse probe did not repeat this asser­tion. However, map­ping soil heat trans­mis­sion glob­ally may help gov­ern­ments advise farm­ers on land man­age­ment prac­tices and deter­mine appro­pri­ate crops to plant in the places under­go­ing the most rapid changes in their envi­ron­ments.

• University of Granada
• Computers and Electronics in Agriculture