80 likes | 235 Views
Resource use efficiency on degraded and marginal lands. Third conference on sustainable agriculture Brussels May 10-12, 2010. Anton Haverkort Sjaak Conijn Wageningen University. Resource use efficiency on degraded and marginal lands.
E N D
Resource use efficiency on degraded and marginal lands Third conference on sustainable agriculture Brussels May 10-12, 2010 Anton Haverkort Sjaak Conijn Wageningen University
Resource use efficiency on degraded and marginal lands Percentage relative yield 100 70 40 10 6.5 6.0 5.5 5.0 4.5 pH 20 30 40 50 60 % Al sat 20 10 5 3 1 ppm P Bray 30 15 8 4 2 meq/100g 01 05 10 15 20 dS/m Mexico, sandy Nigeria, Pfix Brazil, acid Pakistan, salty 6.5 6.0 5.5 5.0 4.5 pH (acidity) 20 30 40 50 60 % Al sat (acidity) 20 10 5 3 1 ppm P Bray (P-fix) 30 15 8 4 2 meq/100g (low SOM) 01 5 10 15 20 dS/m (salt)
Resource use efficiency on degraded and marginal lands Brazil, acid Punjab, salt Yatt 5.4 t/ha Yact 1.6 t/ha Yatt 12.7 t/ha Yact 6.4 t/ha Nigeria, Pfix Mexico, sandy Yatt 8.3 t/ha Yact 5.4 t/ha Yatt 10.9 t/ha Yact 8.2 t/ha
Resource use efficiency on degraded and marginal lands Degraded and marginal lands have lower resource uses Low pH: Low CEC: P-fixation: Salinity: Up to 90 % lower use efficiency of land, water, energy, biocides, nitrate, phosphorus, potassium, lime.
Resource use efficiency on degraded and marginal lands Indicator value pH >6.0 Pavailable >10 ppm P CEC >15 meq/100 g ECe <5 dS/m Sustainable Sustainability threshold Grace period Not yet sustainable Unsustainability threshold pH < 5 Pavailable <3 ppm P CEC < 4 meq/100 g ECe >15 Unsustainable 1 2 3 4 5 6 7 Year
Resource use efficiency on degraded and marginal lands Costs of remediation are enormous Low pH: liming, soil organic matter, P application Low CEC: organic matter amendments P-fixation: P application, soil organic matter Salinity: drainage, soil organic matter, P application Best to avoid degraded soils and avoid them becoming degraded