The diversification of the cropping system can lead to higher yield stability when the cropping system leads to increased soil organic matter.

The soil organic matter ameliorates the effects of drought the major disability factor by increasing the percolation of water aiding in its retention and provision to the crops. In addition the diversification of crops and cover crops improves the diversity and function of symbiotic systems namely the mycorrhizal fungi and rhizobia bacteria.

In addition to water dynamics the effect of soil organic matter is to reduce plant disease and increase plant health and to improve adaptive response.

The Rodale Institute Farming System Trial clearly shows these responses and highlight the mechanisms which control them.

Moritz, just to tell you that this is an empirical usual practice in my country (Burkina Faso). This practice obviously shows a higher yield stability and increases crop's yield. You can test it.

Elucidating the apparent maize tolerance to weed competition in long‐term organically managed systems

• February 2010
• Weed Research 50(1):25 - 36
• DOI:
• 10.1111/j.1365-3180.2009.00750.x
• 📷Matthew R. Ryan
• 📷David A. Mortensen
• 📷L. Bastiaans
• Show all 9 authors
• 📷Paul Reed Hepperly
• This research from Rodale Institute and Pennsylvania State University show how the soil improvement by biologically based organic regenerative decrease the effects of weed competition. The improvement of soil organic matter allows more water and nutrient availability which reduce the weed losses. In relation to this weeds along with drought are biggest variable which plague farmer effort for high consistent yield and quality.

Yes, we recently published the result in Nature Sustainability entitled "enhanced agricultral sustainability through within-species diversfication"

Intercropping which is one of the cropping system on diversification is known to improve yields. Intercropping of cereals and legumes improves cover cropping which enhances moisture conservation and hence the crops are able to make use of other resources from the soil.

Jiasui Zhan thanks for the interesting article. I am looking forward to reading it in more detail. It will be interesting with further research to see if similar results are achieved with other crops, particularly crops that are less disease sensitive. Anyway, nice work!

Moritz Reckling, I think that the answer is going to be 'It depends', and that understanding what type of diversity can be used to increase yield stability in different agricultural systems is an interesting area of research.

Diversifying cropping system via

Changing the year round crop-rotation

Intercropping

Multiple-Cropping

Along with Organic Farming, Precision farming, Integrated Farming etc by combining various components in the farming system can surely contribute to higher yield stability

Changing or diversifying the crops cultivation with alternatives crops of legumes, so the soil fertility will increase and the cultivation of crop will improve.

Work in Minnesota attest to biodiversity working to foster both high biological productivity and capacity to recover from environmental adversity.

Although monoculture foster convenience for farmers they lack biological elements which foster fertility and environmental conservation.

of course, you can read several journals to get more information including: Exploring the integrated crop-livestock systems in different ecoregions of the United States R. Mark Sulca, ∗, Alan J. Franzluebbersb; Integrated Crop / Livestock Agriculture in the United States: A Review KATHLEEN HILIMIRE; Exploring integrated crop-livestock systems in different ecoregions of the United States R Mark Sulc, and others

Dear all,

I agree with the general response that diversification will very frequently lead to stabilisation of yields. There is ample evidence for this, including for within-species diversification, for species mixtures and for diversification across time. However, one thing should not be forgotten: In a diversified cropping system, e.g. in intercropping, the complex interactions between the partners can lead to HIGHER variability of the component yields than in the respective monocultures, even though the combined yield (sum of both partners) fluctuates less in the mixture. This may not be problematic if partners are equivalent, but can pose a problem when they are functionally very different (e.g. a legume and a non-legume).

Best wishes,

Thomas

Thomas you make an interesting and valid point.

Please consider that no matter how the centralized industrialized food system would want to have all controlled under a simplified monopolistic paradigm our diet works off of diversity. The food pyramid is not a corn stalk as the agroindustrial complex is directing toward.

It would be wonderful for the centralized authority to have one plantation producing one crop but that is completely antithetic to nature and nutrition.

I good example would be issues related to high fructose corn syrup. Why grow sugarcane when we can have even a cheaper product from corn monoculture.

The big issue here is since high fructose corn syrup has been introduced the obesity of the human population and its health has plummeted. This is what can be seen as a high cost of cheap food. Cheap for whom and what is the real cost?

The convenience of monocultural systems do not compensate for back end costs which are in reduction in diet and health. The oversimplification of our food system has been engineered by monopolistic interests which are antithetical to the environment, sustainability health and economy all for special vested interests which are enriched off cheap food.

Quantity emphasis needs to balanced with better appreciation of quality and diversity needs to be favored on predatory consolidation of the food and feed system.

Following.

Diversification of cropping can contribute to yield stability as compared with monoculture. Crop rotation will decrease the incidence of plant diseases and give less chances to parasites and insects. Legume crops will enrich the soil in nitrogen.

Hello, Cropping diversification provides a systems approach to reduce yield variations and improve resilience to multiple environmental stresses. Crop diversification strategies increased the probability of harnessing favorable growing conditions while decreasing the risk of crop failure.

Hey Moritz, how you doing?

I assume that you mean it per farm (multiple plots). In this case, the answer might be very different in terms of the farm size (smallholder or big farm), number of plots, and the crop species rotated or intercropped. Also, how long a time series you take into account may show you different results. In addition to 'yield stability', a smooth income per farm may be also interesting.

Greetings from Dresden, Leo.

Hi Moritz,

You can check the meta-analysis by Raseduzzaman and Erik Jensen

Article Does intercropping enhance yield stability in arable crop pr...

However, I am not sure that you will like as they used CV without adjusting it.

Cheers,

Ali

A recent paper by Liu et al 2019 in Field Crops Research supports the hypotheses that diversification of crop sequences increases yield stability in oil seed crops. Their integrated static and dynamic stability assessment showed that a lentil-oilseed sequence was more desirable than a fallow- or wheat–oilseed crop sequence. Article Improving the productivity and stability of oilseed cropping...

Yes, Intercropping may be an answer for diversification as well as enhancement of productivity from unit area. You are requested to go through the attached papers.

The highest functioning soils come from mineralized prairie lands where evaporation and precipitation are close in total quantity to each other and mixtures of grasses and broadleaf perennials can foster a long term soil organic matter accumulation. These grasslands soils have become our preferred bread baskets around the global. Their develop was influenced by grazing. All the plant animal and decomposer elements lead to the ability to gain in soil organic matter. The stability in the productive system can be fostered by an ability to optimize the soil organic matter since the chief limiting factor in our agricultural systems is the ability to optimize water which is a function of organic matter which optimizes the capture retention and recirculation of this critical molecule. The ability to capture water is a function of carbon from the joining of carbon dioxide to water in photosynthesis and continuing the ability of carbon to be conserved and increased in the soil as humus. The ability of stabilized productions in droughts is a function of improving our soils in their carbon content as such it represents our best drought insurance but in addition the soil charged with carbon loses less water so it also mitigates flooding situations. Soil based rather that monoculture agricultural systems are what is needed for a vibrant agriculture and food system in the age of accelerating global warming and climate change. The perennial mixed plant and animals systems are more resilent have less carbon foot print and have significant ability to counteract greenhouse gases which are taken from the enriched atmosphere are beneficially deposited in the soils which have been largely degraded from the previous exploitive agriculture methodology.

Hello Moritz,

Maybe you can find interesting insights in this recent meta-analysis:

https://www.nature.com/articles/s41586-019-1316-y

Cheers,

Germain

We recently conduct a systematic review submitted to synthetize results on effet of crop diversification on vulnerability/resilience/robustness of yields. It will contribute to answer this question with the mains highlight : it seems that dynamics of yield are driven by composition effect (and thus functional diversity), but globally diversity lead to desired dynamics (low variability, resistance, rapid recovery ...) Follow me to receive more information when will be published. See also latest paper in nature of Wang et al. 2019

Thanks for all the valuable feedback, I hope to discuss this issue further during the "European Conference on Crop Diversification 2019" 18th - 21st September 2019, Budapest, Hungary https://www.cropdiversification2019.net/ e.g. during Session 5: Enhancing agrosystem resilience and performances by crop diversification

Dear Moritz,

I agree with the general statement that diversification is likely to reduce yield variability. I our work, we analyzed this concept by applying the Portfolio Theory (don't put all your eggs in one basket) and showed that some diversification strategies can outperform others, depending on which eggs and which basket you choose. (see: https://www.researchgate.net/publication/328996818_Reducing_risk_through_crop_diversification_An_application_of_portfolio_theory_to_diversified_horticultural_systems)

In addition, I totally agree with Thomas Döring, that in intercropping systems, where crops interact with each others, the resulting variability can be higher than the respective monocultures. This issue has been raised early by Rao, Willey and Vandermeer in the ealry 90's. We deal with this concept bringing a new approach in a paper that is currently under review and will be published soon, but we can exchange about it.

It will be a pleasure to meet you at the ECCD at Budapest !

Regards

Raphael Paut

Here our recent contribution at the ECCD in Budapest Conference Paper Does cropping system diversification with legumes lead to hi...

Yes, it does! Diversification is very important for achieving sustainable production under changing climatic scenario...

Crop diversification does not necessarily work in a vacuum.

The focusing on the state of the soil and especially soil organic matter is where the rubber meets the road.

If the diverse cropping system is effective in increasing depleted soil organic matter the stability of the system will increase as water dynamics are the biggest limitation to overall cropping system performance.

If the crop diversity leads to soil improvement the stability of the system will likely increase if that is not the case the results will be compromised.

In a depleted system the addition of stabilized organic matter in the form of finished compost can increase the stability of the crop yield in cropping systems which are mostly limited by the water dynamics.

https://www.mssoy.org/uploads/files/varvel-2000.pdf

Title: Crop Rotation and Nitrogen Effects on Normalized Grain Yields in a Long-Term Study

Article Modeling yield Sustainability for different rotations in lon...

Title: Modeling yield sustainability for different rotations in long-term barley trials

Cropping system yield stability in response to plant diversity and soil organic carbon in temperate ecosystems

• Hida R. Manns and Ralph C Martin
• 2018: Agroecology and Sustainable Food Systems 42(5):1-27.
• DOI: 10.1080/21683565.2017.1423529

Another good example for diversification (at the species level): Article Heterogeneous Winter Wheat Populations Differ in Yield Stabi...

There is no doubt!

Yes, cropping system has enough potential to assure yield stability and agricultural sustainability. Particularly, inclusion of legumes has a lot of advantages as adaptation option against climate change and global warming.

Millets are ecologically hardy, C4 plants, wider adaptability, can produce satisfactory yield where other crops can't be grown under different types of stress. Further, millets are re-evaluated as 'nutri-cereals' considering their food values.

Very true Dr Sagar Da... Yes, diversifications in the cropping systems through the inclusion of suitable legumes and nutri-cereals are the need of the hour....

@Biswajit, thanks for your valuable comments.

Yes, diversification leads to minimization of risk and contributes towards sustainable yield and farmers income. But may not be true for higher efficiency in short run.

In the diversification of the crop system rotation needs to consider complementarity of the species. For instance 3 sister planting of Ameri Indian cultures featured maize, beans, and squash.

The maize function as a living pole and beans grown would use the maize as support and the squash understory provided a soil cover and weed control. The mixture of the species improved the diet as every component complemented each other, the ability to improve soil and the ability to decrease on compensate for pests and diseases are important.

Legumes can be very critical in the anchoring of production systems as they provide scarce nitrogen for cereal staples and eliminate many of soil pathogen issues related to monocultures.

Work in North America show that soybean as a previous crop can increase yield potential about 18% for maize and in the case of maize before soybean the soybean is increased about 18% also. In the case of soybean it needs no Nitrogen input which reduces the overall Nitrogen input 50%.

The dependence of ammoniated fertilizer can have long term negative effect on soil pH and other sustainability issues.

Thanks for sharing your views and articles.

I would like to share our recent paper "Livestock integration into soybean systems improves long‑term system stability and profits without compromising crop yields". It does not directly explore cropping diversification or plant species diversity, but crop-livestock integration as a way to achieve greater system stability. I hope you enjoy the reading and that it contributes to the debate somehow.

Article Livestock integration into soybean systems improves long-ter...

Thanks for sharing this informative piece of work!

Several studies have demonstrated that crop diversification enhances soil fertility, controls for pests and diseases thus improving yield.