Image copyright Science Photo Library Image caption Women account for only a small proportion of skilled scientists worldwide

Policy and business leaders have used a major food conference to highlight the need for more women in the global agriculture sector.

One of the speakers, Chelsea Clinton, told delegates that women were a "crucial, vital and necessary" part of delivering global food security.

Data shows that progress has been made in recent years, but there is still a long way to go to close the gender gap.

The call for equality was made at the 2015 Borlaug Dialogue in the US.

"Certainly, we are not on track at the moment to feed the population we expect to have around the world in 2050," Ms Clinton, vice-president of the Clinton Foundation, told the gathering.

One of the themes of the three-day event, which focused on the "fundamentals of global food security", was inspiring young women to take up careers in science, technology, engineering and mathematics (Stem).

Global problem

Another speaker, Wanjiru Kamau-Rutenberg - director of the Kenya-based African Women in Agricultural Research and Development (Award) - outlined some of the challenges.

"We need to increase the number of women scientists but first of all we need to create a conducive environment in which they work. It is as much about institutional transformation as it is about investing in individuals," she said.

"It can be a little too easy to pretend that this is only an African problem, hence a cultural problem. But that is not true; we have got the same challenge in the UK, across Europe and in the US.

Image copyright Reuters Image caption Chelsea Clinton: "We are not on track to feed the population we expect to have around the world in 2050"

"It is a global problem so we have to change the global culture surrounding science and who can be a scientist."

A report produced by the Campaign for Science and Engineering (Case) that examined diversity in UK Stem said that just 9% of those involved in non-medical Stem posts were women.

However, it also highlighted that the problems facing the science sector in the UK went beyond gender equality. The authors reported that there was an annual shortfall of 40,000 skilled Stem workers.

Dr Kamau-Rutenberg told the BBC the shortfall illustrated why it was critical to attract more young women to pursue careers in the Stem sector.

"We need to expand the pool of talent and increase the number of scientists. Investing in women scientists is a really good way to solve the problem of not enough scientists being available to do the work."

Mentoring

She said Award offered a career development programme that was "investing in high-potential African women and agricultural scientists".

As well as developing technical skills, Award provided leadership training and a mentoring network.

"We just know that people do so much better at achieving their potential as a result of mentoring - when they are in a community of peers and when they are connected to senior scientists," she said.

Dr Kamau-Rutenberg added that just under half of the mentors in the network were men: "This is fantastic because we are able to engage men in this journey of investing in women scientists."

Image copyright Reuters Image caption President Obama: "Any nation that fails to educate its girls or employ its women is doomed to fall behind"

She said that a speech by US President Barack Obama, during his visit to Kenya in June, showed the importance of giving women the opportunity to "earn a place at the decision-making table".

Mr Obama had told a gathering at a sports stadium: "Any nation that fails to educate its girls or employ its women and allow them to maximise their potential is doomed to fall behind the global economy.

"We're in a sports centre. Imagine if you have a team and don't let half of the team play. That's stupid. That makes no sense."

Beyond the farm gate

Data from the UN Food and Agriculture Organization (FAO) shows that the gender gap extended to access to agricultural resources and opportunities.

The FAO said: "Closing the gender gap in agriculture would generate significant gains for the agriculture sector and for society.

"If women had the same access to productive resources as men, they could increase yields on their farms by 20-30%."

Dr Kamau-Rutenberg went further: "It is not enough to talk about African women in agriculture and leave the conversation at the farm level.

"There is no point pretending that the only place it is important to talk gender, and the roles of men and women in agriculture, is on the farms.

"We also need to transform the landscape when it comes to research and development. It is really important that we have both men and women setting the research agenda."