Green manures offer many advantages:
• they prevent soil compaction due to rainfall, they limit the development of weeds, their roots aerate the soil
• they enrich the soil as they decompose,
• their flowers attract pollinating insects!
• In contrast, chemical fertilizers feed the plant but leave the soil poor.
Sainfoin and Phaceliea form part of the green manures that are appreciated for their ability to fertilize the soil, their honey-producing qualities and their attractive colours. They are regularly sown in plots left fallow after vines have been uprooted. They re-seed from one year to the next, and for several years they have been found amid vines and in borders and embankments.
Sainfoin:
• is one of the fodder legumes used to increase the fertility of soil by providing nitrogen back to the soil via nitrogen fixation.
• facilitates decompaction and loosening of the soil due to its dense and deep taproots, and in addition its cultivation will leave soil almost free of weeds, protecting it against erosion.
Phacelia is rich in nitrogen and phosphorus, which it extracts from the soil through its deep roots and then returns these nutrients during its decomposition.
These plants are of interest on flowering fallow land, especially for bees which produce a delicious creamy honey, but that’s not all: they preserve biodiversity by attracting pollinating insects (bees, butterflies, hoverflies, etc.), as well as small mammals and birds.
They both offer a significant plant biomass that protects the soil from compaction during heavy rains.