Amid reminiscences of childhood days spent milking cows, picking berries and splitting logs, the Senate voted overwhelmingly yesterday to let children as young as 10 work as harvest laborers under some conditions.

Senator after senator rose to proclaim the virtures of learning good work habits, breathing fresh farm air and discovering the value of the dollar at a young age.

Most of them came from states such as Maine and Oregon where growers of crops like potatoes, strawberries and raspberries have been objecting to a 1974 congressional ban on employing children under 12 in agricultural work. Previously there was no law setting a floor under the age for farm work.

"I would wager today that children are safer picking strawberries, raspberries or beans than they are playing in the park," said Sen. Bob Packwood (R-Ore.) "They are not likely to be mugged or robbed or raped in the strawberry field . . . They may be in the park."

Sen. Mark O. Hatfield (R-Ore.) called the proposal a "constructive opportunity for leisure time," and Sen. William D. Hathaway (D. Maine) said it allows children to get out-of-doors and "oftentimes they are engaging in play with one another" while picking crops. Sen. Edmund S. Muskie (D-Marine), who noted that he split logs at age 6, arritbuted "much of the disaffection with government" to rules like the 12-year age minimum for farm work.

Sen. Jacob K. Javits (R-N.Y.), sounding the one discordant note among the rapsodies, challenged his colleagues' suggestions that field work was a good way for youngster to earn "pin money." "Do we let them sell cocaine because they want pin money, or steal groceries because they want money?" asked Javits, who said he was opposed to any weakening of child labor laws, which is the position taken by the Labor Department.

Packwood said that he, as a "product of the field," could understand the distinction. Javits, Packwood, noted grew up in "the asphalt jungle."

In the end, the Senate at the urging of Javits and Sen. Harrison A. Williams Jr. (D.-N.J.), adopted work restrictions considerably tighter than a previously passed House measure that would empower the Secretary of Labor to authorize field work at any age if conditions such as need for workers, health protection and proimity to home are met. The Senate-approved bill would impose a 10-year age floor limit the time a youngster can work in the fields to eight weeks, ban exposure to pesticide, and require the Labor Secretary to determine that.