Arguably the progenitor of small grain agriculture in the fertile crescent. Maslins are the understudied solution to many problems. The oldest research paper I can find on them is from 1995. Between then and now there have been few papers or articles.
Now only commercially cultivated in a few pockets of the world, they were once one of the foundations of most food systems. Ethiopia and Georgia are the two areas still practicing maslin growing at a larger scale. India, Portugal and the United States are also doing smaller studies.
A group of researchers from Cornell and Addis Ababa University are the current people spearheading this work. Thanks to them we have empirical data points such as certain wheat and barley varieties preforming 11 and 20 % better sewn in a maslin instead of a monoculture.
Wheat and barley maslins seem to be the current research sweethearts. Historically many other combinations were used depending on the local context. Ethiopia seems to have the broadest range of current practices, typically harnessing sorghum and maize in low land areas and incorporating wheat and barley in their highlands.
The primary sources available for this topic are so limited due to this practice being almost completely lost to mechanized agriculture. Through the grapevine I have managed to find out the typical maslin for my part of Canada is rye, barley and oats. Originally referred to as "dredge corn".
Dredge corn was used primarily for animal feed and to mill into flour, some also used it in beer brewing. The biggest benefit to this arrangement is the diversity of moisture and temperature ranges it can tolerate. Especially when combining multiple varieties, it will select for a composition most suited to the area over the years. Ie. the drought tolerant varieties will continue to propagate and be resewn in drought susceptible areas.
We have been exploring maslins for a while and may soon release a few arrangements.