More than half of the nation's teachers say they see evidence of child abuse, poor nutrition and parental neglect in their classrooms, according to a national study.

"Teachers repeatedly made the point that in the push for better schools they cannot do the job alone, and yet there is a growing trend to expect schools to do what families, communities and churches have been unable to accomplish," said Ernest L. Boyer, president of the Carnegie Foundation for the Advancement of Teaching.The foundation's survey of 22,000 teachers found a sense of frustration among teachers, both at "the lack of support they receive from parents" and from a feeling of "powerlessness in teaching," he said.

"Large majorities of teachers find poverty, poor health, undernourishment and neglect to be problems at their schools," he said.

Teachers from every state were canvassed in twin surveys conducted by mail in the spring and fall of 1987. The findings were released Sunday.

Among them:

-90 percent said lack of parental support was a problem at their schools.

-89 percent said there were abused or neglected children at their schools.

-69 percent said poor health was a problem for their students.

-68 percent said some children were undernourished.

Teachers in the survey described their students "as `emotionally needy' and `starved for attention and affection,' " Boyer said.

Mary Hatwood Futrell, president of the National Education Association, said the report underscores the need for parental involvement.

"I wish I could sit down with every parent in America and emphasize how important they are to their children's education," Futrell said. "Parents are a child's first - and potentially the most influential - teachers."

The average public school teacher earned $28,031 in 1987-88, according to figures from the NEA.

Forty-nine percent of the teachers in the Carnegie survey said their pay was worse than they expected; 41 percent said it was about what they expected; and 10 percent said it was better. The average teacher surveyed had 16 years' experience.

The average teacher faced 79 students on a typical day, with elementary teachers working with 60 different pupils and secondary teachers 114.

The typical class size was 23. Sixty-two percent of the teachers said their most typical class was about the right size; 36 percent felt it was too large, and 1 percent said it was too small (The figures do not add up to 100 percent because of rounding).