Primary school teachers and principals say Government policies are behind a drop in teacher morale and a jump in the number of schools that do not have enough staff.
A survey at 351 primary and intermediate schools last year by the Council for Educational Research identified the trends and warned schools need more help.
It found nearly all teachers and principals enjoy their work, but they are finding it increasingly difficult.
The survey is conducted every three years. It said the percentage of teachers reporting good or very good morale has slipped from 86 percent to 74 percent.
It also found only 29 percent of principals believe their staffing is sufficient, down from 48 percent in 2010.
The Educational Institute and the Principals Federation blame policies such as the national standards in reading, writing and maths for the fall in morale.
The study found little support for the national standards - its findings on that were published last year.
Education Minister Hekia Parata acknowledged the drop in morale, but said that will improve when government initiatives create new leadership roles and reduce teachers' paperwork.
She said investment in teacher quality should help reduce complaints about inadequate staffing and, she said, Government funding for schools has kept pace with inflation over the past five years.