Project Number
WW 02-07
Project title
Evaluation of Different Cover Crop Species and Cover Crop Management Practices According to Soil Physical and Chemical Qualities, Water Consumption and Performance of Grapevines in a Sandy Soil at Lutzville
Project leader
Fourie, J C
Team members
Louw, P J E
Kotzé, J J
Project description
Alternative cover crop species are being researched in a field trial at Lutzville with the aim to supply guidelines for effective cover crop management in the irrigated vineyards of regions with a warmer climate. Twenty-three treatments, consisting of six cover crop management practices applied selectively to seven cover crop species and two cover crop mixtures, as well as a mechanically cultivated control with no cover crop, were applied.
Full surface irrigation is essential for cover crop management on the sandy soils of the Olifants River Valley and adjacent regions. In a dry year with water restrictions, as experienced during the past season, rye yielded the highest amount of dry matter. The dry matter yield of grazing vetch and pink Seradella was the highest if weekly irrigation or rainfall of 18 mm each for a period of four weeks after sowing could be followed by an irrigation of 18 mm every third week. All the cover crops can be sown for at least five consecutive seasons on these sandy soils. Grazing vetch and the two Medicago species were the only species that could re-establish themselves partially. Despite the hard coat of the seeds of these species, the seed population only built up if the growth of these cover crops exceeded the level of one ton of dry matter per hectare. A level of 10 mg. kg-1 of P and 78 mg. kg-1 of potassium in the 0-300 mm soil layer seems sufficient to supply in the needs of grazing vetch. Saia oats, however, needs a total of 30 kg P, 30 kg K and 42 kg N during establishment and at the six leaf stage to produce a significant amount of dry matter. Pink Seradella, grazing vetch and Paraggio medic produced additional dry matter from the beginning of September to mid-October following a dry winter. Additional irrigation water (at least 49 mm. ha-23rd-1), is, however, necessary to make it happen. The cover crops, with the exception of rye, did not reduce the vegetative growth or grape production of the Sauvignon blanc/Ramsey vines, if left to continue growing after budbreak, provided that additional irrigation is applied and that the oats species and pink Seradella are controlled chemically during mid-October. The nitrogen status of the vines, however, was initially reduced, but reached normal levels after the fourth year in full production. Fertilisers can be withdrawn totally for a period of five years, without any detrimental effect on the vines, provided that grazing vetch is used as cover crop. In doing so, an average reduction in input cost of R337 ha-1 Lyra-1, compared to mechanical cultivation, was measured over a period of eight years. In the case of pink Seradella, N could eventually also be omitted from the spring application of fertilisers.
Cover crop management sustained, and in some instances even improved, the organic matter content in the 0-150 mm soil layer of this organically poor sandy soil. All the cover crop treatments were economically more viable than the mechanically cultivated control.
The project is in an important phase. Extension guidelines will be adjusted according to the results obtained in the coming two seasons. During this period the soil organic matter content and soil mineral status will be determined and the long-term effect of the treatments on the soil quantified. Intensive root and penetrometer studies will be executed at the end of the 2002 – 2003 season, to determine the effect of the treatments on root growth and soil compaction, whereafter the results of this long-term project will be published. In doing so, the project should terminate by June 2004, with the submission of a final report one year before the scheduled end date.
Presentation(s)
Fourie, J C. 2001. Evaluation of different cover crop species and cover crop management practices as suitable soil cultivation practices for integrated grape production in the Olifants River Valley and adjacent regions. Cover Crop Information Day, 27 September, Lutzville Experimental Farm, Lutzville.
Fourie, J C. 2001. Dry matter production and weed control achieved with different cover crop species and the effect of different management practices on cover crop performances. Cover Crop Information Day, 27 September, Lutzville Experimental Farm, Lutzville.
Fourie, J C. 2002. Evaluation of different cover crop species and cover crop management practices for soil management within the integrated grape production framework in the Olifants River Valley and adjacent regions. Winetech Information Day, 25 September, Vredendal.
Fourie, J C. 2003. Cover crop management in vineyards and orchards. Nexus Farmers’ Meeting, 21 May, Paarl.
Fourie, J C. 2004. Chemical control of cover crops in vineyards. Radio Elsenburg, 6 August.
Fourie, J C. 2005. Cover crop management as part of integrated production of table grapes in the Hex River Valley. 5 April. Terason Famers Day, De Doorns.
Fourie, J C. 2005. The management of cover crops in grapevines from the end of August until berry set. 12 August. Radio Elsenburg.
Fourie, J C. 2005. Weed control and management practices to restrict weed resistance to herbicides. South African Society for Enology and Viticulture Table and Drying Grapes Short Course, Upington, South Africa.
Fourie, J C. 2005. Weed control and management practices to restrict weed resistance to herbicides. South African Society for Enology and Viticulture Table Grape Short Course, 10 August, Rawsonville, South Africa.
Fourie, J C. 2005. Organic production: the cultivation and economic realities. South African Society for Enology and Viticulture Table Grape Short Course, 10 August, Rawsonville, South Africa.
Fourie, J C. 2005. Weed control and soil cultivation guidelines for the integrated production of grapes. Visit of Technical Leadership Institute to ARC Infruitec-Nietvoorbij, 30 August, Stellenbosch, South Africa.
Fourie, J C. 2005. Weed control and soil cultivation guidelines for the integrated production of grapes. Visit of Technical Leadership Institute to ARC Infruitec-Nietvoorbij, 6 September, Stellenbosch, South Africa.
Fourie, J C. 2006. Chemical weed control in the vineyards of the Lower Orange River region. Modular Course in Table and Drying Grape Cultivation, 11 May, Kakamas, South Africa.
Fourie, J C. 2006 Effect of different soil surface management practices on the soil and grapevines in the Lower Orange River region. Modular Course in Table and Drying Grape Cultivation, 11 May, Kakamas, South Africa.
Fourie, J C. 2006. Low cost and sustainable soil cultivation practices for table and drying grapes in the Lower Orange River region.
Article
Fourie, J C, Louw, P J E, Agenbag, G A. 2002. Die geskiktheid van verskillende dekgewasse vir volhoubare deklaagbewerking in die wingerde van die Olifantsriviervallei en omliggende gebiede, WineLand, Mnth May (p. 75-78)
Fourie, J C, Louw, P J E, Agenbag, G A. 2002. Dekgewasbestuur en wingerdprestasie in die Olifantsriviervallei, WineLand, Mnth Sep (p. 103-108)
Fourie, J C, Louw, P J E, Agenbag, G A. 2005. Cover crop management in Sauvignon blanc/Ramsey vineyard in the semi-arid Olifants River Valley, South Africa. Part I. Effect of management practices on selected grass and broadleaf species, South African Journal of Enology and Viticulture, v. 26 (2) (p. 131-139)
Article.pdf
Fourie, J C, Louw, P J E, Agenbag, G A. 2007. Cover crop management in Sauvignon blanc/Ramsey vineyard in the semi-arid Olifants River Valley, South Africa. Part II. Effect of different cover crops and cover crop management practices on grapevine performance, South African Journal of Enology and Viticulture, v. 28 (2) (p. 81-91)
Article.pdf
Fourie, J C, Louw, P J E, Agenbag, G A. 2007. Cover crop management in a Chardonnay/99 Richter vineyard in the coastal region, South Africa. Part III. Effect of different cover crops and cover crop management practices on organic matter and macro-nutrient content of a sandy soil, South African Journal of Enology and Viticulture, v. 28 (1) (p. 61-68)
Article.pdf