More than 250 PhD students receive their PhDs at WUR every year. It is impossible to describe and summarize all these theses. In the column ‘PhD theses in a nutshell’ the selection of our science editors is briefly presented.
Grass cuttings as fertilizer
Grass cuttings from road verges can be used to improve the soil, Maartje van der Sloot has proven. Verge compost can halve the nitrogen consumption of fields of maize and winter wheat without affecting the yield. This was shown by a large-scale three-year trial run by Van der Sloot. The only problem was the litter. You do have to extract that from the compost first. This is one of the reasons farmers are still hesitant about using verge cuttings. Moreover, the nitrogen and carbon content of the compost has to be exactly right to have the desired effect on the soil.
Road verge cuttings as organic amendment on arable fields
Maartje van der Sloot. Supervisor David Kleijn
A goner
Fusarium fungi are a serious threat to global banana cultivation. Einar Martínez de la Parte, from Cuba, studied the sensitivity of 18 Cuban varieties of eating and cooking bananas to the Fusarium fungus Tropical Race4. Bad news: none of them proved resistant. This makes the pathogen a potential threat to 56 per cent of Cuba’s current banana plants. But there’s more bad news: the fungus survives easily in various weeds, and strikes from that base. The researcher says his study shows how important it is to protect the crop from the fungi. If we don’t, the banana will be a goner.
Fusarium wilt of banana in Cuba
Einar Martínez de la Parte. Supervisor Gert Kema
Restoring the balance
Babies’ guts are sensitive to antibiotics, which disturb the normal development of the gut flora. And that can affect the child’s susceptibility to diseases later in life. Martha Florencia Endika, from Indonesia, researched whether supplements in baby food (certain indigestible hydrocarbons) can restore those gut flora. You can guess the answer. Yes, they can, but it depends which antibiotic is used, what the gut flora looked like before it was given, and what you add to the baby food. She didn’t test it on real babies, by the way, but on an in vitro model.
Gut Rebalancing Acts
Martha Florncia Endika. Supervisors Hauke Smidt and Koen Venema (Maastricht University)
