Climate change demands that governments throughout Africa, including Zimbabwe, should now "rethink the legal structure of land tenure."
That means tenants should "rather pay a fixed share of the harvest than a fixed amount of money."
A new study finds that if African governments encouraged a system of "sharecropping", the resilience of agriculture production in the face of climate change-induced crop failures or famines would increase.
Through sharecropping, tenants do not pay a fixed amount of money to landowners. Instead, they pay a fixed share of the harvest, usually 50 percent.
"Since these are not fixed costs, this system makes farmers more robust against crop failures", explained Matthias Kalkuhl, co-author of the study which was produced by German climate research institute MCC.
Published in the journal Ecological Economics, the research states: "According to our calculations, this can make African agriculture more efficient and thus increase food security. By comparison, sharecroppers less frequently resort to forms of risk management that tend to reduce yields."
Such measures include the omission of fertilisation in order to preserve liquidity, and excessive livestock farming as a precaution against crop failures, said the study.
There are three land tenure models in Zimbabwe:
the A1 small-scale permit system,
the A2 medium-scale leasehold system (both resulting for the fast track land reforms of the early 2000s, abolishing freehold tenure)
and the communal land tenure model.
The state-based tenure system has generated difficult problems for farmers intending to access bank loans using their land as collateral security.
However, small-scale and communal farmers have largely remained in control of their land, something that cannot be said of farmers in other parts of Africa.
The charge towards industrial, commercial agriculture throughout much of Africa has dispossessed small farmers of their land, turning them into hungry labourers on their own farmlands.
For example, in Mozambique, a majority of peasants lost their land when they entered into asymmetrical relationships with domestic and foreign agrarian capital in sugar cane farming, according to researchers from the Sam Moyo African Institute of Agrarian Studies in Harare.
Now, the Zimbabwe Government is at the forefront of advocating alternative models of farming that include contract farming and joint venture partnerships, as part of efforts to attract capital to a grossly under-funded agriculture sector.
But experts are worried about the potential impacts, even for a sector that has seen loans for farmers from commercial banks plummet to just US$6 million in 2008 from US$315 million ten years earlier.
They are concerned about how foreign agricultural investments may interact with issues of land rights, power relations, social and economic entitlements and inequalities between large agribusiness and smallholders.
"The advent of such models requires a closer examination as there is a potential of undermining the peasantry base through land alienation, in some cases labour exploitation, and unequal exchange of surplus value which occurs through input and output markets," observed Freedom Mazwi et al, of the Sam Moyo Institute.
Contract farming is known to often leave farmers in sustainable debts. Joint ventures will not do much for farmers receiving a fixed amount of money and not the produce.
The risks of food insecurity resulting from climate change-triggered crop failures for small farmers are too ghastly to contemplate.
Already, Zimbabwe is in the middle of severe food shortages, with only about 100 000 tonnes of grain -- enough only for a month's supply -- remaining in the country, says Agriculture Minister Perrence Shiri.
This follows a series of poor harvests caused by a succession of droughts over the past two farming seasons, events blamed on the rapid changes in climates.
About 800 000 tonnes of maize will now be bought from outside the country.
In the MCC study, authors used an extraordinary structural survey from the period 2002 to 2005.
About 9 600 typical farms in eleven African countries were identified at that time and questioned about their general conditions and agricultural methods.
The study also included historical weather data at these locations.
"The heterogeneity in climate conditions is larger than ever studied before in this context", stated MCC researcher Kalkuhl.
"We find that low levels of precipitation increase the prevalence of sharecropping. Climate change will change precipitation values. This is why this issue is becoming a political priority".
In recent decades, African countries have adopted land law reforms aiming at individual registration and titling of land.
To date, over two dozen African countries have proposed "de jure" land law reforms "that are extending the possibility of access to formal freehold land tenure to millions of poor households," According to Freedom Mazwi et al.
Examples include Zambia in 1995, Uganda in 1998, Côte d'Ivoire in 1998 and 2015, Malawi in 2002, Kenya in 2012, Mozambique in 1997 and 2007 and Tanzania in 1999 and 2015.
"The objectives explicitly aim to clear the way for full privatisation and commoditisation of farmland. These land policy developments have implications on possible land policy trajectories for Zimbabwe going forward," Maz0wi stated.