director selling, page-15

this might be your answer:

http://au.news.yahoo.com/thewest/business/a/-/business/6677409/minemakers-closer-to-nt-phosphate-production/

note quote AD:
"Prices for fertiliser are rising quite quickly, so we see it switching quite quickly from last year, which was very much a buyer's market."

Prices for phosphate - which is used in fertiliser - have fallen sharply from early 2008 highs. However, the signing of a key supply contract last month effectively established a global floor price for potash, another fertiliser ingredient. Phosphate prices rose as much as 15 per cent in December.