Know more

About cookies

What is a "cookie"?

A "cookie" is a piece of information, usually small and identified by a name, which may be sent to your browser by a website you are visiting. Your web browser will store it for a period of time, and send it back to the web server each time you log on again.

Different types of cookies are placed on the sites:

  • Cookies strictly necessary for the proper functioning of the site
  • Cookies deposited by third party sites to improve the interactivity of the site, to collect statistics

Learn more about cookies and how they work

The different types of cookies used on this site

Cookies strictly necessary for the site to function

These cookies allow the main services of the site to function optimally. You can technically block them using your browser settings but your experience on the site may be degraded.

Furthermore, you have the possibility of opposing the use of audience measurement tracers strictly necessary for the functioning and current administration of the website in the cookie management window accessible via the link located in the footer of the site.

Technical cookies

Name of the cookie

Purpose

Shelf life

CAS and PHP session cookies

Login credentials, session security

Session

Tarteaucitron

Saving your cookie consent choices

12 months

Audience measurement cookies (AT Internet)

Name of the cookie

Purpose

Shelf life

atid

Trace the visitor's route in order to establish visit statistics.

13 months

atuserid

Store the anonymous ID of the visitor who starts the first time he visits the site

13 months

atidvisitor

Identify the numbers (unique identifiers of a site) seen by the visitor and store the visitor's identifiers.

13 months

About the AT Internet audience measurement tool :

AT Internet's audience measurement tool Analytics is deployed on this site in order to obtain information on visitors' navigation and to improve its use.

The French data protection authority (CNIL) has granted an exemption to AT Internet's Web Analytics cookie. This tool is thus exempt from the collection of the Internet user's consent with regard to the deposit of analytics cookies. However, you can refuse the deposit of these cookies via the cookie management panel.

Good to know:

  • The data collected are not cross-checked with other processing operations
  • The deposited cookie is only used to produce anonymous statistics
  • The cookie does not allow the user's navigation on other sites to be tracked.

Third party cookies to improve the interactivity of the site

This site relies on certain services provided by third parties which allow :

  • to offer interactive content;
  • improve usability and facilitate the sharing of content on social networks;
  • view videos and animated presentations directly on our website;
  • protect form entries from robots;
  • monitor the performance of the site.

These third parties will collect and use your browsing data for their own purposes.

How to accept or reject cookies

When you start browsing an eZpublish site, the appearance of the "cookies" banner allows you to accept or refuse all the cookies we use. This banner will be displayed as long as you have not made a choice, even if you are browsing on another page of the site.

You can change your choices at any time by clicking on the "Cookie Management" link.

You can manage these cookies in your browser. Here are the procedures to follow: Firefox; Chrome; Explorer; Safari; Opera

For more information about the cookies we use, you can contact INRAE's Data Protection Officer by email at cil-dpo@inrae.fr or by post at :

INRAE

24, chemin de Borde Rouge -Auzeville - CS52627 31326 Castanet Tolosan cedex - France

Last update: May 2021

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

Home page

Change in C levels and stocks in soils

Organic C levels increase in soils that receive OWP and decrease in the control plots. The increases are largest for GWS compost and FYM, slightly lower for BIO compost and even lower for MSW compost. The input of mineral N acting on the biomass from crop residues also increases organic C levels in soils. The BSI appears to be a good indicator of the humic balance (increase in organic C measured in the soil, compared with the quantity of organic C input via OWP).

Organic C levels in soils

The organic C levels measured in the soils are shown in Figure 1.

Evolution-stock-C-org-sol_1998-2011_72-dpi
Figure 1. Change in organic C levels in the soils in the N fertilized plots since the begining of the experimentTable 1. Change in organic C levels in the surface levels of the different treatments (in % compared with the average initial levels in the treatments)
Augmentation-C-org-sol_1998-2011_Fr_72-dpi_large

Organic C levels in the soils increased in all of the plots receiving OWP and decreased in the control plots. The export of wheat straws undoubtedly explains the decline in organic C levels in the control plots, as well as the fall in the production of biomass from crop residues in the section not complemented with mineral N.

In the section not receiving any mineral N, organic C concentrations in the surface level are significantly higher (than the 5% threshold) in all organic treatments compared with the control, from 2002, i.e. after two spreadings. In the section receiving mineral N, these differences are significant in 2004.

Organic C levels in the soils differ according to the OWP input, even though the OWP doses provide the same quantity of organic C (4 t/ha). Organic C levels in soils receiving GWS compost, BIO compost or FYM are significantly higher than those in soils receiving MSW compost, from 2004 in the section with no mineral N and in 2006 in the section of the system receiving mineral N. In the section complemented with mineral N, the input of organic C by crop residues temporarily conceals the effect of the input of OWP (input of 20 t C/ha in all treatments). 

MSW compost appears to be less effective than the other OWPs studied at increasing the organic C stock in the soil. This is linked with the biodegradeability of its organic matter, which is higher than that of the other OWP.

The OWPs also act through their effect on the biomass from crop residues: 17 t C/ha (BIO compost), 18 t C/ha (GWS and MSW compost) and 19 t C/ha (FYM).

Calculation of humic performance based on the change in the organic C stock

The humic performance measured corresponds to the increase in organic C measured in the soils compared with the quantity of organic C input by the OWP. These coefficients are shown in Table 2 for each OWP and are compared with the BSI values. Their aim is to estimate the proportion of stable organic C liable to enrich the soil. MSW compost appears to be the least effective at increasing the organic C stock in the soil.

 
Table 2. Average humic performances of OWPs and comparison with the BSI

C stock 1998

C stock 2011

Increase of C in soil from 1998 to 2011

C input by the 9 spreadings

Humus yield

Average yield

Average BSI

t C / ha

-

-

-

GWS + N

40,5

59,7

19,7

34,4

0,57

0,62

0,42

BIOW + N

41,2

58,3

18,4

30,7

0,60

0,66

0,50

MSW + N

39,7

49,1

9,1

29,3

0,31

0,36

0,37

FYM + N

40,7

55,1

15,1

32,9

0,46

0,52

0,44

CTR + N

40,9

40,0

-

-

-

-

-

GSW

39,4

58,6

22,8

34,4

0,66

-

-

BIOW

39,9

58,2

22,4

30,7

0,73

-

-

MSW

39,5

47,8

12,1

29,3

0,41

-

-

FYM

40,3

55,0

19,2

32,9

0,58

-

-

CTR

39,8

35,8

-

-

-

-

-