Sorghum’s Plant Physiology and Research
About 95% of all crop plants are referred to as C3 plants. Sorghum is referred to as a C4 plant.
(Edwards et al., 2010) tells us that “the C4 photosynthetic carbon cycle is an elaborated addition to the C3 photosynthetic pathway. It evolved as an adaptation to high light intensities, high temperatures, and dryness. Therefore, C4 plants dominate grassland floras and biomass production in the warmer climates of the tropical and subtropical regions”.
C3 plants have the normal photosynthetic pathway in which the CO² is first fixed into a 3-carbon compound. In C4 plants, the first compound after CO² fixation is a 4-carbon compound.
The C4 plants of importance in agriculture are sugar-cane, corn, sorghum and millet.
In C3 species the rate of photosynthesis increases with rising CO², while in C4 plants that have a more efficient system of utilising and storing CO², the response to high levels of CO² in atmosphere is much less, (e.g. these plants photosynthesise faster at normal CO² levels and therefore have a higher water use efficiency than C3 plants, and also better tolerance to heat and drought).
With the challenge of global warming requiring attitudinal change and industry innovation in the world’s cropping systems, sorghum cultivars are ideal crops to be trialled in the sub-tropical regions, and especially those regions experiencing more than their normal cycle of drought and heat.
For instance, in July 2015, ABC Rural News posted a story from Queensland, Australia titled ‘Sorghum beats wheat as Queensland’s most valuable cereal crop’. A spokesperson for the Queensland Alliance for Agriculture and Food Innovation Professor David Jordan acknowledged the benefits of nearly 50 years of study and research into this crop.
As far back as fifteen years ago in 2001, scientists working at the University of Queensland published a paper to the journal Phytogen (Vol.3 No.2, September 2001) pressing sorghum’s claim as a more desirable food crop.
|1.||Based on yield average in your location and the availability of water, apply granular fertiliser at suitable rates as top-dress or with the seed to match the target yield. Make sure that seeds are treated with BSN Superstrike in advance to maximise the yield potential of the grain by elevating nutrient levels in seed lot. BSN Superstrike is highly advantageous in sorghum since sorghum seeds show low level of trace elements and phosphorus with large variability of these nutrients in the
|2.||Apply 0.5L of Crop Specific Foliar (e.g. K-Komplex, Cereal Plus or Plasma Fusion) along with an equal volume of a Power N product per tonne of target yield/h at 4 to 5 leaf stage. This mixture can be applied with 40-100 litres of water. Higher rate of water is beneficial in dry conditions.|
|3.||If sorghum is grazed and then left for seed, or if higher yield is expected with irrigation or higher rainfall, a second application of the above mixture is beneficial at leaf stage 8 or later.|
Sorghum should no longer be considered as simply ‘animal feed’, as it currently is in the majority of western and developed markets an d food cultures.
As highly placed research continues to uncover many of Sorghum’s qualities and benefits, with its important potential role in the hu man food chain as a health protecting cereal crop, so its place in the market will grow.
With global warming, and the issues of climate change bringing about management and crop-selection challenges and changes for the agricultural industry, sorghum should be factored into crop growing regimes. This is particularly so in areas that are undergoing consistent or prolonged increased temperature change and other weather and climate related changes. Its properties have been sho wn, because of its unique plant structure to be beneficial in this regard.
Sorghum rightfully can own its tag as a ‘wonder crop’, and understanding its qualities and benefits will only bring about better outcomes for global agriculture as it seeks to meet its food production goals. Sorghum is a crop for both humans and livestock that because of its unique qualities can adapt to the climate challenges ahead.