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

Home page

Humic balance of spreadings

The theoretical change in C content in soils is calculated according to the humic balance proposed by Hénin-Dupuis (1945) and compared with results measured in the field. The theoretical results based on the BSI or OMSI are very satisfactory and correlate with the field measurements.

Principle of the humic balance

Every year, a K2 proportion of the organic matter (OM) in soils is mineralised. These losses through mineralisation are offset by the incorporation of crop residues and the spreading of organic waste products (OWP). Only a K1 proportion of the organic C entering into the soil via the residues and OWP  helps to offset the mineralisation of OM in the soil.
The annual balance of inputs and outputs can be used to calculate the theoretical change in OM levels in the soil surface horizon:

C (t+1) = C(t) - K2 . C(t) + K1PRO . CPRO(t) + K1RES . CRES(t)

C(t): the level of organic C over time t,
C(t+1): the level of organic C over time t+1,
COWP(t): the flow of organic C through OWP inputs,
CRES(t): the flow of organic C through the incorporation of crop residues,
K1ROP and K1RES: the proportions of organic C from OWP and crop residues that enrich the level of organic C in the soil,
K2: the proportion of organic C in the soil that is mineralised each year:

K2 = [ 0,03 . (1 + 0,2 . (TMA - 10) ] / [ (1 + 0,005 . Arg) . (1 + 0,0015 . CaCO3) ]

AAT: the annual average temperature,
Clay: the clay content of the soil,
CaCO3: the carbonate content of the soil.

Calculating the humic balance in the QualiAgro field experiment

The values taken into account for the QualiAgro field experiment are as follows:

K2: 0.0206 (AAT: 11°C, Clay: 150g/kg soil, CaCO3: 0)
K1RES: 0.13
K1OWP is estimated based on the BSI, the OMSI or the RL
(for an overview of these indicators see Characteristics of OWP).

The change in the organic C content in the soil C(t) is compared with the values measured in the soil.
The results of the calculation with the BSI or the IROC produced satisfactory results that are well correlated with measurements in the field (r2: respectively 0.90 and 0.92). The RL produces the poorest results (r2 of 0.73).
The results obtained are slightly underestimated with the BSI and overestimated with the IROC. As such, the change in organic C content in the soil can be calculated based on the BSI and the IROC, which provide the low and high points of the actual change.

EN_c_calc_Cmeasured_72 dpi

Figure 1-a.  ISB comparaison

 

EN_c_calc_Cmeasured-iroc_72 dpi

Figure 1-b.  ISMO comparaison

Figure 1. Comparison of C content measured in the soils of the various treatments from 1998 to 2006, with C content calculated based on the humic balance, taking into account the annual mineralisation of organic C in the soil and inputs of C through crop residues and supplies of OWP: the BSI and OMSI indicators are compared with the K1ROP coefficient of the humic balance.

flèche précédent
RikikiBulleEfficacitéAgronomique
flèche suivant