OAT VS WHITE MUSTARD AS CATCH CROP
Background. The number of species suitable for late summer sowing as catch crops intended for mulching soil is insufficient. It has been hypothetically assumed that oat (Avena sativa L.) may be an alternative to white mustard (Sinapis alba L.) that is commonly grown for this purpose. The aim of this study was to compare the yield and nitrogen accumulation of oat and white mustard planted as catch crops at different late summer dates, and the effect of mulch from these plants on spring barley (Hordeum sativum L.) yield.
Material and methods. In the period from 2011 to 2013, oat and white mustard were sown separately on August 15 and September 1 and 15. No nitrogen fertilization was used for the catch crops. At the end of October, dry matter accumulation and nitrogen accumulation were determined. Photographic documentation of the mulch coverage of the soil was made. Over a 3-year period (2012–2014), spring barley was grown after the oat and mustard mulch. Plant density and grain yield of the barley was determined.
Results. Delaying the sowing date resulted in a decrease in catch crop dry matter accumulation, on average for both species, from 2.36 to 0.61 Mg·ha-1, and in nitrogen accumulation from 45.4 to 30.3 kg·ha-1. Differences in biomass and nitrogen accumulation, in favor of mustard, were associated with the earliest sowing date only. Oat plants did not lose leaves in winter and thus provided greater soil cover than mustard plants. These species cultivated as a catch crop and used for mulch did not differ in their effect on plant density or spring barley yield.
Conclusion. In crop rotations with a large proportion of cruciferous plants, oat may replace white mustard to capture residual N and to mulch the soil, however its sowing date should not be later than the beginning of September.