The Convention on the Elimination of All Forms of Discrimination against Women (CEDAW) - currently ratified by 187 countries - is the only human rights treaty that deals specifically with rural women (Art. 14). Adopted in 1979 by the United Nations Generally Assembly, entered into force in 1981. The Convention defines discrimination against women as follows:
For the purposes of the present Convention, the term "discrimination against women" shall mean any distinction, exclusion or restriction made on the basis of sex which has the effect or purpose of impairing or nullifying the recognition, enjoyment or exercise by women, irrespective of their marital status, on a basis of equality of men and women, of human rights and fundamental freedoms in the political, economic, social, cultural, civil or any other field (Art. 1).
The Convention covers civil and political rights, as well as economic, social and cultural rights. Notably, it contains obligations on State Parties also in respect of discrimination by private parties, or in private contexts. Furthermore, CEDAW considers both de jure (in law) and de facto (in practice) discrimination. States that ratified - or otherwise acceded to - the Convention are legally bound to put its provisions in practice, even if they made reservations, which shouldn't be in any way "incompatible with the object and purpose" of the Convention (Art. 28).
Because it sets an international standard of women's human rights in areas such as education, employment, health care, marriage and family relations, politics, finance, and law, CEDAW provides a platform for lobbying governments to promote gender equality and hold them accountable at international level. CEDAW has been an important advocacy tool of the women's movement over the last 30 years.
States Parties of the Convention should submit periodic reports to the CEDAW Committee on the legislative, judicial, administrative or other measures which they have adopted to give effect to the provisions of the Convention (Art. 18). Civil society can present "shadow reports".
Art. 14, 15 and 16 of CEDAW specifically deal with rural women, ownership of land, inheritance rights and right to access property. You can read the Convention on the OHCHR website, where you can also find information on past and current Sessions of the CEDAW Committe, including official States' Reports and civil society "shadow reports", the Committee's Concluding Observations, and General Recommendations.
Finally, you can find information for NGO participation.