The chief of the Marin Agricultural Land Trust resigned last week after just nine months in the position, becoming the latest of several high-ranking MALT staff members to depart in the last two turbulent years. Thane Kreiner joined MALT as C.E.O. in March, taking the helm as the trust was reeling from conflict-of-interest accusations. Now, as MALT works to defend itself from public funding cuts, Mr. Kreiner is leaving, citing a new career stage consisting…