City officials and philanthropists announced two new early childhood initiatives today. From left: Administration for Children's Services Commissioner Ronald Richter, Mayor Bloomberg, Chancellor Dennis Walcott, and Susie Buffett, of the Buffett Early Childhood Fund.

Instead of waiting until children are turning five years old to start educating them, the Department of Education is going to start targeting some children at five weeks.

Citing research that shows a correlation between long-term achievement and enrollment in high-quality early childhood programs, Mayor Bloomberg announced this morning that the city will open a school next year that enrolls children from infancy through pre-kindergarten — and their parents.

Bloomberg also announced a $20 million initiative to turn 4,000 oft-unused half-day pre-kindergarten seats into full-day slots that many parents find more attractive.

Bloomberg and Schools Chancellor Dennis Walcott made the announcements today in conjunction with “Education Nation,” NBC’s annual extravaganza of education policy programming hosted in Midtown Manhattan. This year’s summit is focusing on innovations that have been proven to work.

One of those is early childhood education, which primes children for academic success in elementary school and beyond. Children’s minds are already 85 percent developed by the time they are old enough for kindergarten, a 2005 study found, and early education advocates say interventions in infancy can have a far greater impact on the achievement gap than at any other period in children’s lives.

In the proposed new school, which would open next September inside Brownsville’s P.S. 41, low-income parents would be pushed to develop stronger social and emotional skills with their children while the children are infants and toddlers. Ultimately serving between 115 and 125 families a year, the school will be part of the Educare Schools network, which already operates 17 early childhood schools in 13 states.

In Educare schools, “the first thing that [parents] do is they hold [their children] and talk to them and look them in the eyes,” said Susie Buffett, daughter of philanthropist Warren Buffett and chair of a foundation that is a major donor to the network. She said interaction with adults who share their knowledge with children is not only “the foundation of literacy, but it’s also the foundation of curiosity, self-confidence, self-control and the ability to persist in hard tasks.” (This research is detailed in “How Children Succeed,” the new book by Paul Tough.)

The Educare school’s facility design calls for many large open spaces as well as smaller rooms where children and parents can work together while being observed. Renovations to P.S. 41 could cost up to $20 million, Walcott said, with half coming from the Department of Education’s capital funding and the other half coming from private donations.

Officials said they could not yet estimate the cost to operate the school once its space is complete, but they said 80 percent of the costs could be borne using federal and state funding streams that already pay for a constellation of early childhood programs. The other 20 percent will need to be matched by private donors, whom Bloomberg said he has yet to find.

Ultimately, officials said today, the Educare school could become a model for applying “attachment” interventions citywide, even in schools not designed specifically to foster them.

The second early childhood initiative that the mayor announced this morning would break less ground. Instead, by funneling more city funds into supporting full-day pre-kindergarten spots, the city will be taking an action that advocates have been demanding for years.

Currently, state funds for pre-kindergarten can only be used to fund half-day programs. While many programs pitch in to extend the day for their students, the city ends up returning about $30 million a year to the state in pre-kindergarten funding because many families steer clear of half-day programs.

“If you’re a working parent or parents, and you need to have your child in a full-day program because that’s more convenient, you may not enroll [in a half-day program] because of that,” said Sophia Pappas, executive director of the city’s Office of Early Childhood Education. “We think that is one of the big barriers.”

Last year, Comptroller John Liu urged the city to lobby the state for permission to use pre-kindergarten funding for full-day programs, something the city had done before. But in the absence of a state policy fix, the city has decided to use $20 million of its own funds to grow its pre-kindergarten capacity by 4,000 seats.

The new seats will represent a 25 percent expansion in the number of full-day pre-kindergarten seats operated by the Department of Education. Until now, 16,000 of the city’s 60,000 pre-kindergarten seats have fallen into that category, with the rest being a mixture of half-day programs and programs offered by the Administration for Children’s Services.

Only about 58,000 of the seats are filled each year, officials said, and about 7,500 eligible children are not enrolled in any kind of pre-kindergarten program. The enrollment rates being lowest in poorer neighborhoods, the officials said.

The announcements drew praise from advocates who are usually Bloomberg’s fiercest critics. Zakiyah Ansari, advocacy director of the Alliance for Quality Education and a mother of eight children who attended city schools, said she welcomed the new initiatives.

“In this climate of the economic crisis, education budget cuts, school closings and lay-offs, I am happy to see that Mayor Bloomberg, City Council and the NYC Department of Education are prioritizing our youngest students and giving them a chance to succeed,” Ansari said.