Evidence of healthy roots extensive
white color growth into the sub-soil Healthy shoot growth and good minimalproliferate in all yields evidence of directions deformities Efficient use of soil resources
Understanding corn root developmentThe seed
roots stopgrowing shortly after the coleoptile emerges from the soil surface. The nodal root system becomes visible at ~ V1. The nodal root system becomes the dominant system by V6.
All you need to do
to grow healthy roots is use rootworm resistant genetics… right??When rootworm pressure is high, rootworm resistant genetics normally result in much healthier roots
Rootworm resistant genetics are not
a silver bullet ! Severe damage by corn rootworm larvae to roots of a corn rootworm hybrid http://www.ipm.iastate.edu/ipm/icm/2006/11-13/btcorn.html
We have witnessed the historically
low densities of European corn borers across Illinois and some nearbystates that are now believed to be linked to the widespread adoption of Bt corn hybrids. Will we see a similar phenomenon unfold with western corn rootworms? I suspect we might be headed down this road. Will westerncorn rootworms adapt as they have repeatedly done so in the past? If we dont integrate management tactics, we could have the answer sooner than we would like.
Ken Ferrie’s perspectiveAs the root
moves through the soil it tapersdown, but when it hits a sudden densitychange, ‘it’s like a fly hit the screen. It’s too Verticaltight and it twists, bends and runs tillage toolhorizontally," said Ferrie."What causes the sudden density change? Ken Ferrie – Farm JournalCompaction. If it hits a compacted layer, it turnsand runs on top of it."Ferrie added the drastic change is caused by afarm in horizontal tillage. "You can’t use horizontaltillage without putting in a horizontal layer"Horizontal tillage creates loose soil on top and afirm shelf underneath, and the density changecreates difficulties for roots which are trying topenetrate the firmer layer.
Wading pools filled with compost
are *not* an optimal rooting environment but are an example of the plasticity of plant root systems. With limited rootingvolume but adequate water and nutrients, it is possible to grow abundant crops.
Prevention through improved drainage maybe
the most effective strategy Artificial drainage has greatly increased the number of days when soils are suitable for deep root growth but has also contributed to many Pollution of environmental water resources problems Loss of SOM
Understanding aluminum toxicity Fe and
Mn toxicities also occur at lower pHs Toxic forms of Al are bioavailable at pHs < 5.5 Aluminum toxicity is minimal above a water pH of 5.5 http://www2.ctahr.hawaii.edu/tpss/research_extension/rxsoil/alroot.gif
Galled root system of tomato
infected with root-knot nematode, Meloidogyne sp., compared with non- infected root system Root pathogens can inhibit root growth http://www.agnr.umd.edu/users/nrsl/entm/nematology/images/eis143.jpg
Both strategies are important !Feed
the soil vs. Feed the crop??? Unhealthy roots use nutrients inefficiently… Healthy roots need available nutrients ! Healthy roots grow in soils with a favorable balance Acute of air, water and root soil organic matter disease Chronic root malfunction
Absorptive network for limiting soil
resourcesof water and nutrientsMechanical structures that support plants,strengthen soil, construct channels, breakrocks, etc.Hydraulic conduits that redistribute soil waterand nutrientsHabitats for mycorrhizal fungi, rhizosphereand rhizoplane organisms
Carbon pumps that feed soil
organisms and contribute to soil organic matter Storage organsChemical factories that may change soil pH, poison competitors, filter out toxins, concentrate rare elements, etc.A sensor network that helps regulate plant growth
Inoculation groups for commonly grown
legumesAlfalfa Group Alfalfa (Rhizobium meliloti) Black medic Bur clover Button clover White sweetclover Yellow sweetcloverClover Group Alsike clover (Rhizobium trifolii) Arrowleaf clover* Ball clover Berseem clover Crimson clover Hop clover Persian clover Red clover Rose clover* Subterranean clover* White cloverCowpea Group Alyceclover (Bradyrhizobium japonicum spp.) Cowpea Kudzu Peanut