Canola is well known as a rotation crop because it’s a useful tool to break disease cycles associated with monoculture, and it helps reduce herbicide resistance by allowing farmers to vary their crop protection programmes. Canola is a member of the genus Brassica that produces isothiocyanates when the roots and leaves decay, suppressing soil pathogens and disease. Canola also has a deep tap root that loosens soil, thus improving air, water and nutrient movement. This leads to better water use by follow-up crops, as well as better nitrogen uptake, in turn reducing the risk of soil acidification and waterlogging. All this results in follow-up crops with healthier root systems that are less susceptible to disease. “Research has found that canola can boost the yield of follow-up crops such as maize and wheat by up to 25%,” says Petrus Fouché, CEO of PhytoPharming the agricultural division of PhytoEnergy SA. “Better yield was measurable up to the fourth year after canola was planted.” Canola’s tap root also renders it more drought resistant than most other field crops. He recalls Jan Horn, a farmer from Heidelberg in the southern Cape, harvesting more than 1t/ha of canola compared to only 0,9t/ha of wheat after five months of drought from April to August 1993. “Namaqualand farmer Hennie van Wyk planted canola and barley during dry conditions in 2003,” explains Petrus. “Barley, despite its drought-resistant reputation withered, while canola grew actively.”
Petrus says that by incorporating canola into rotation programmes, Free State farmers can have four harvests in four years with maize and wheat, and five harvests by adding canola to the rotation.
To ensure a good stand of canola as a dual-purpose crop, it should be planted with the last summer rain from January to March in the Eastern Cape, KwaZulu-Natal and the Free State. In the Western Cape it can be planted at the end of February with the first autumn rain.
Canola as grazing
Canola should be grazed no shorter than ankle height, preferably while still in a vegetative stage. A high-density, quick graze would be most effective, but farmers should use the condition of the veld and their production requirements as a guide.
Petrus experimented with 20 canola cultivars at Langgewens near Moorreesburg. They were cut to simulate grazing around eight weeks after planting, while some were left to grow without interference as control. The grazed cultivars on average produced 2,2t/ha, while the control produced around 2,4t/ha. The grazing effect is relatively insignificant considering that it helps to reduce animal feed costs. Additional fertiliser should be used when grazing is planned.
Petrus says problems with planting canola only occur with incorrect management practices. “We measured a mean rainfed canola yield of 2,2t/ha in the Eastern Cape at Zingqa despite late planting, insufficient fertiliser and aphid problems. There’s no reason why other farmers can’t achieve similar results.”
Herbicide resistance
One of the main mistakes causing yield problems is a failure to follow herbicide instructions. “When canola was first introduced to South Africa, farmers produced between 2t/ha and 3t/ha,” recalls Petrus. “But production has dropped even though improved cultivars have been introduced. I believe it is mainly due to negligence with sulfonylurea herbicides.” Farmers must ensure the withholding period has been met before planting canola on treated lands. Spraying carts should be properly cleaned after using a sulfonylurea product.
Hormone-based herbicides, such as MCPA or 2,4D should also not be sprayed near or downwind from canola.
The Herbicide Resistance Action Committee warns that herbicides break down more slowly in soil with a pH of above 6,5 and where the soil has recently been limed. Minimum or no-till can increase the withholding period as it causes herbicide to break down more slowly. Other factors that can lengthen the withholding period include below-average rainfall followed by dry summers and high sulfonylurea or double dosages.
Planting regiments
Petrus says the smaller canola seeds need better seed-to-soil contact and moisture in the top soil for germination than larger wheat or maize seeds do. If the seedbed is too fine or overworked, it loses moisture and easily develops a crust.
Canola seed can be planted at around 2kg/ha to 3kg/ha, depending on production practices and soil conditions. He says a narrow-press wheel with oval or rounded profile is preferred. The wheel results in better seed-to-soil contact and even ripening.
Seed shouldn’t be planted deeper than 2cm to 3cm, depending on soil moisture and time of planting. Deep planting takes longer to germinate, so canola is more susceptible to soil-borne diseases and insects. Herbicides should be used to reduce competition between canola and weeds. Petrus adds that canola is frost-resistant up to -7°C to -9°C. As a result, there are few places where canola won’t thrive due to frost.
Contact Petrus Fouché on 082 779 1609 or e-mail [email protected]. |fw
A nutritional animal feed
Another huge advantage of canola is that it can be used as animal feed. Canola produces almost double the amount of drymatter per hectare at between 11t and 15t, compared to oats at between 6t/ha to 8t/ha on pasture. It has a higher protein content of 17,7% compared to oats (15,6%), and total dry nutrients of 65,8% compared to 60,7% in oats, as well as metabolisable energy of 9,88mJ/kg compared to 9,11mJ/kg in oats.
Its non-digestible fibre content is lower at 40% than oats at 65%. Canola can also be used as a dual-purpose crop for grazing and seed production. Trials in the Western Cape, Free State and the Eastern Cape revealed hybrid canola produced 21,1t/ha of green forage, which equates to 3,43t/ha of drymatter, eight to 10 weeks after planting. This additional value in milk, meat or wool covers input costs, so the seed harvest is almost all profit.
A farmer near Caledon, George de Kock, had a 1,5t/ha seed yield after planting in the first week of April and grazed 12,5 sheep per hectare during June and July.
Canola’s financial benefits
A canola-wheat rotation will increase profit by between R1 000 and R1 500/ha, according to economic research by Dr Willem Hoffmann and Prof Theo Kleynhans at the agriculture department of the University of Stellenbosch.
Production and price analysis also showed a canola-maize-wheat rotation would result in a R2 000/ha increase in gross margin.
Petrus says these results are simply because of a higher follow-up crop yield. Using canola as a dual-purpose crop would be even more financially beneficial considering it produces about R3 000/ha if 3,4t/ha DM is produced at R900/t.
The biodiesel refinery
The biodiesel refinery and all other buildings around it, to be completed by 2011, will cost about €250 million (R3,5 billion). PhytoEnergy SA and its BEE partners are responsible for capital layout. PhytoEnergy SA forms part of the European PhytoEnergy Group with projects in India and the Ukraine. The group is also negotiating with various German and SA financial institutions to acquire further funding. Long-term supply agreements have been secured in Europe.
PhytoPharming CEO Petrus Fouché says European Regulations assume a rise in demand of around 14 million tons per year until 2015, and 28 million tons from 2020 (depending on assumed blending ratios of 7% until 2015 and 10% until 2020). The domestic market is expected to grow by about 180 000t/year in the next two to five years. Silos will be available from 2010 to stock enough canola in the ramping-up phase. Petrus conservatively estimates the refinery will result in 500 000ha of underutilised land going into production.
The project will benefit producers in the Free State where silos will be made available for delivery in Marquard.
Possible canola rotations
A maize rotation without canola
Year 1: Maize is planted in Oct.
Year 2: Four months fallow after harvest (Jun/Jul) followed by maize planted in Oct/Nov.
Year 3: Four months fallow after harvest (Jun/Jul) then maize planted again in Oct/Nov.
Year 4: Four months fallow after harvest (Jun/Jul) then maize planted in Oct/Nov.
Year 5: Four months fallow after harvest.
Year 6: Fallow continues into the 6th year for a year of fallow.
Wheat, canola, maize and sugar-graze sorghum
Year 1: Wheat is planted in Jul, harvested Dec, followed by one to two months fallow.
Year 2: Canola is planted in Feb/Mar, grazed eight to 10 weeks after planting. Harvest is Oct.
Year 3: Four months fallow followed by maize planted in Oct, harvested Jun/Jul.
Year 4: Six months fallow after harvest.
Year 5: Canola is planted in Feb/Mar and grazed eight to 10 weeks after planting. Harvest is Oct.
Year 6: Sugar-graze sorghum is planted Oct.
A maize rotation with canola
Year 1: Maize is planted in Oct.
Year 2: Six months fallow after harvest (Jun/Jul).
Year 3: Canola is planted in Feb/ Mar and grazed after eight to 10 weeks, harvested Oct. Maize is planted directly after harvest.
Year 4: Four months fallow after
harvest followed by maize planted in Oct.
Year 5: Cycle of previous year repeated.
Year 6: Fallow.
Wheat, canola and maize
Year 1: Wheat is planted in Jul and harvested Dec, followed by one or two months of fallow.
Year 2: Canola is planted in Feb, grazed after eight to 10 weeks after planting, then harvested in Oct and planted with maize.
Year 3: Four fallow months, then maize is planted in Oct. Harvest is Jun/Jul.
Year 4: Six fallow months after maize.
Year 5: Canola is planted in Feb, harvested in Oct. Or wheat planted in Jun, harvested Dec.
