The mixture of white mustard and forage rye produced excellent biomass on this soil type and performed somewhat better than the mixture of forage oats, triticale and forage peas. The rye produced good biomass, while the triticale was average in terms of biomass production. The mixture of oats and stooling rye worked well with the stooling rye producing notable biomass. The phacelia and radish were patchy where these species had been sown by hand, as was the faba bean cover (one of the challenges of small scale field trials). Where these cover crops had been sown in another section of the block using the planter, results were far better with even, dense growth.

Where the phacelia was sewn using the planter, it produced an excellent stand with purple flowers which attracted many bees. The medics which had been sewn by hand on the grapevine row underneath the drippers, was a huge success at this site. Although medics is not aggressive in its growth habit, it did reach just below the cordon wire at various points in the block. This required a team to walk through the block and trample the medics flat on one occasion early in the season. At the time of evaluation, the medics was nearing the end of its life cycle and would be expected to set seed and die off by the end of spring.

Treatment	Recommended Sowing Rate kg/ha	Performance	Approximate Seed Cost R/ha	Photos taken
White mustard + forage rye	3 + 30	Very good/Excellent	675
Forage oats + triticale + forage peas	20 + 40 + 15	Good/Very good	800
Rye	45	Good	675
Triticale (2 species)	100	Average	800
Phacelia	7	Average (by hand) Excellent (planter)	805
Premix: oats (3 species) and stooling rye	40	Very good	693
Forage radish and vetch	2+10	Good	600
Faba beans	80	Average (by hand) Very good (planter)	950
Medics (on the bankie)	5	Excellent	495

District: Paarl
Year: 2019
Demo Site: Olifantskop, Wellington
Soil Description: Weathered granite
Sowing Date: Mid-late April 2019

The mixtures of forage rye with peas and forage rye with bitter lupines were the best performers on this challenging soil type, providing good biomass and weed suppression. The rye, bitter lupines and vetch produced average biomass. The phacelia’s biomass was poor and the mixture comprised of three different oats species with stooling rye, performed reasonably well. The importance of top dressing was illustrated by the clear difference in the density and height of the stands between the ‘top-dressed’ and non-‘top-dressed’ treatments.

Treatment	Recommended Sowing Rate kg/ha	Performance	Approximate Seed Cost R/ha	Photos taken
Forage rye + bitter lupins	30 + 20	Excellent	650
Forage rye + forage peas	30 + 15	Very good	700
White mustard + oats + vetch	1.5 + 20 + 6	Good	630
Rye	45	Average	675
Bitter lupins + vetch	40 + 8	Good	580
Triticale	100	Good	750
Premix: oats (3 species) + stooling rye	40	Good	693
Phacelia	7	Average	805

All the mixtures performed well at this site. The forage rye in the forage rye and vetch mixture flourished and outperformed all the other cereals and species at this site. The white mustard produced very good stands with and without oats. The mixture of forage barley, forage peas and radish, which offers a good balance of biomass production, nitrogen fixation and bio tillage, produced good biomass and suppressed weeds. The mixture of oats, radish, stooling rye and vetch provided a dense stand with substantial biomass. The mixture of triticale and lupines also performed excellently. The phacelia produced moderate amount of biomass which was comparable to the phacelia growth at other sites in 2019. Although the medics and clover cover was recommended for application on the grapevine row, it grew extremely well in the work row at this site. It is recommended that medics be sown on the grapevine row to provide a good ground cover that is not expected to grow into the grapevine canopy.

Treatment	Recommended Sowing Rate kg/ha	Performance	Approximate Seed Cost R/ha	Photos taken
Forage rye + vetch	25 + 6	Excellent	670
White mustard + Saia oats	3.5 + 25	Excellent	570
White mustard	8	Excellent	592
Forage barley + forage pea + radish	25 + 20 + 1.5	Very good	650
Oats + stooling rye + radish + vetch	30	Very good/Excellent	950
Bitter lupines + triticale	25 + 60	Excellent	655
Phacelia	7	Average	805
Medics + clover (on the bankie)	3 + 2	Excellent	470

At this demo site, forage rye produced considerable biomass and provided good weed suppression. The standard rye was less impressive in terms of biomass and had begun to dry out in late September, which is perhaps an advantage if water resources are limited and a chemical spray is to be avoided. The black (Saia) oats produced excellent biomass but suppressed the bitter lupines to a degree. An increase in the sowing rate of the bitter lupines sowing rate would overcome this. The forage radish also developed well on this soil and produced good above and below-ground growth.

Treatment	Recommended Sowing Rate kg/ha	Performance* (Biomass production, even development of the stand and weed suppression)	Approximate Seed Cost R/ha	Photos taken
Forage rye	45	Excellent	695
Rye	55	Good	695
Saia oats + bitter lupines	25 + 30	Very good	590
Forage radish + vetch	2 + 10	Good/Very good	600

*Performance is an overall indication of the quantity of biomass produced, the development of the stand in terms of even or patchy growth and the degree to which the cover crop suppressed weeds.

The lack of rain in the Robertson and Worcester region in 2019 created challenging growing conditions, and cover crop growth was largely unsuccessful in these regions.

District: Robertson
Year: 2019

The lack of rain in the Robertson and Worcester region in 2019 created challenging growing conditions, and cover crop growth was largely unsuccessful in these regions.