Nature Sub-Journal: Mixed cultivation can get higher yield

Nowadays, monoculture occupies the dominant position of cultivated land, and a large area of ​​land is occupied by a single, promising high-yield variety

Mixed cultures provide a potential choice for a single culture

A team led by Professor Christian of ETH Zurich has now revealed that in arable agriculture, mixed cultures actually produce higher yields than single cultures

Principles of Applied Ecology

Mixed culture draws on ecological principles, that is, where there is greater biodiversity, ecosystems can perform their functions more effectively

This also applies to agroecosystems: "Studies of grassland used in agriculture show that areas with more mixed plants are more productive than areas with only one or a few plants," Schb said

So far, hardly any similar research has focused on arable agriculture

The researchers created two test gardens: one in the Ilchel campus of the University of Zurich in Switzerland, and the other in the Extremadura province of Spain

Higher yields with a mixture of two crops 

In their experiments, the researchers selected two or four different crops from eight selected crops, including wheat, oats, quinoa, lentils, lentils, flax, and false flax (a kind of rapeseed-like Oilseeds) and coriander

The researchers compared the seed quality of mixed and monocultured crops

The results speak for themselves: Compared with single planting, even the mixed planting of two crops increased production in Spain by 3% and in Switzerland by 21%

The researchers explained that this additional yield is mainly due to the biodiversity effect: more plant species can make better use of existing resources and more effectively control natural pests-experiments without the use of pesticides Proceed

Plants inject a lot of energy into the leaves and stems 

However, the researchers also pointed out that compared with single cultivation, mixed cultivation plants will grow more leaves or stems

He attributed the fact that plants invest more energy in creating nutrient biomass to the species used in the experiment

Schb believes that seeds suitable for mixed cultivation may have greater potential for additional yield

Over time, people changed most crops to produce larger fruits and higher yields under single cultivation conditions

Sow the right seeds 

As far as the current situation is concerned, no seeds are produced or sold specifically for mixed cultures

However, if mixed culture is to make progress, changes in agricultural practices are required
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In addition, the machine needs to be able to harvest different crops at the same time and separate different harvested products
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"These machines do exist, but they are few in number, let alone expensive
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" There is too little demand for them
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"Combined with optimized seeds and the right machines, a hybrid culture will provide a real opportunity for the future of farmers
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Chen JG, Engbersen N, Stefan L, Schmid B, Sun H, Schöb C: Diversity increases yield but reduces reproductive effort in crop mixtures, Nature Plants , 2021, published online 24th June.
Doi: 10.
1038/s41477-021-00948-4