Know more

Our use of cookies

Cookies are a set of data stored on a user’s device when the user browses a web site. The data is in a file containing an ID number, the name of the server which deposited it and, in some cases, an expiry date. We use cookies to record information about your visit, language of preference, and other parameters on the site in order to optimise your next visit and make the site even more useful to you.

To improve your experience, we use cookies to store certain browsing information and provide secure navigation, and to collect statistics with a view to improve the site’s features. For a complete list of the cookies we use, download “Ghostery”, a free plug-in for browsers which can detect, and, in some cases, block cookies.

Ghostery is available here for free: https://www.ghostery.com/fr/products/

You can also visit the CNIL web site for instructions on how to configure your browser to manage cookie storage on your device.

In the case of third-party advertising cookies, you can also visit the following site: http://www.youronlinechoices.com/fr/controler-ses-cookies/, offered by digital advertising professionals within the European Digital Advertising Alliance (EDAA). From the site, you can deny or accept the cookies used by advertising professionals who are members.

It is also possible to block certain third-party cookies directly via publishers:

Cookie type

Means of blocking

Analytical and performance cookies

Realytics
Google Analytics
Spoteffects
Optimizely

Targeted advertising cookies

DoubleClick
Mediarithmics

The following types of cookies may be used on our websites:

Mandatory cookies

Functional cookies

Social media and advertising cookies

These cookies are needed to ensure the proper functioning of the site and cannot be disabled. They help ensure a secure connection and the basic availability of our website.

These cookies allow us to analyse site use in order to measure and optimise performance. They allow us to store your sign-in information and display the different components of our website in a more coherent way.

These cookies are used by advertising agencies such as Google and by social media sites such as LinkedIn and Facebook. Among other things, they allow pages to be shared on social media, the posting of comments, and the publication (on our site or elsewhere) of ads that reflect your centres of interest.

Our EZPublish content management system (CMS) uses CAS and PHP session cookies and the New Relic cookie for monitoring purposes (IP, response times).

These cookies are deleted at the end of the browsing session (when you log off or close your browser window)

Our EZPublish content management system (CMS) uses the XiTi cookie to measure traffic. Our service provider is AT Internet. This company stores data (IPs, date and time of access, length of the visit and pages viewed) for six months.

Our EZPublish content management system (CMS) does not use this type of cookie.

For more information about the cookies we use, contact INRA’s Data Protection Officer by email at cil-dpo@inra.fr or by post at:

INRA
24, chemin de Borde Rouge –Auzeville – CS52627
31326 Castanet Tolosan CEDEX - France

Dernière mise à jour : Mai 2018

Menu Logo Principal logo SOERE PRO Logo CIRAD Logo AnaEE Logo IRD Logo Ouagadougou university

Home page

Crop yields

The spreading of OWPs increases crop yields over time. The effects are cumulative and add up over the long term. In the case of maize, after 7 spreadings the OWPs achieve the same yields as in plots receiving optimal nitrogen fertilisation. These results indicate that OWPs could potentially act as a substitute for mineral fertilisation while also guaranteeing the same yields. The effects are less pronounced on wheat. The yields, which are on the rise, have not yet exceeded those of mineral fertilisation.

Crop yields after 12 years

The average crop yield at the start of the test was 101.5 and 84.8 t of maize per ha for grain and 104.5 and 88.8 t/ha for stalks.
The yields in 2010, after 7 spreadings, are shown in Figures 1 and 2.
The spreading of OWPs has a significant positive effect on yield compared with the control in the absence of nitrogen fertilisation (around 52% higher). These effects are less pronounced in the case of additional optimal nitrogen fertilisation. In this case, only the manure treatment shows a significantly higher yield than the control plot receiving nitrogen. The other treatments show higher yields, but not significantly so.
Meanwhile, the input of ROPs without nitrogen fertilisation achieves yields comparable to those obtained in the control plots receiving nitrogen. The cumulative effects of the 7 spreadings potentially enable nitrogen fertilisation to be abandoned.

Figure1.quintaux-de-MS-ha-mais

Figure 1. Grain yields expressed in quintals of DM/ha for maize in 2010 (solid shading for crops receiving optimal nigrogen fertilisation, hatching for crops not receiving additional fertilisation). The differences observed between the control treatment and the OWP treatments are significant in the absence of nitrogen fertilisation; with nitrogen fertilisation, only the manue treatment shows a significant difference compared with the control (Mann-Whitney non-parametric test).

Figure2

Figure 2. Maize stem and leaf yields expressed in quintals of DM/ha for maize in 2010 (solid shading for crops receiving optimal nitrogen fertilisation, hatching for crops not receiving additional fertilisation). The differences observed between the control treatment and the OWP treatments are significant in the absence of nitrogen fertilisation; with nitrogen fertilisation, only the manure treatment shows a significant difference compared with the control (Mann-Whitney non-parametric test).

Change in the crop yield following successive spreadings

The positive effect of spreadings on the yield is gradual over time. It results from the effects of successive spreadings, as shown by the comparison of yields between plots only receiving ROPs and the control plots receiving nitrogen (Figure 3).
The figure represents the relative yield from OWP treatments alone, compared with the control + optimal nitrogen fertilisation treatment. Until 2005, this relative yield is below 1, which means that the input of OWPs alone does not equal the yields obtained with nitrogen fertilisation alone. By contrast, from 2005 in the case of maize, yields with OWPs are higher than those with nitrogen fertilisation. For wheat and barley (2007), the relative yields remain below 1. However, they have shown a continued increase since the start of the test, which may indicate that over the long term, yields with OWPs will exceed yields with mineral fertilisation alone.
These results also show the study's importance over the long term in the analysis of OWP spreading.

figure3.traitement-PRO

Figure 3. Change in relative yields from OWP treatments without nitrogen fertilisation compared with the control treatment with optimal nitrogen fertilisation.