The Harold K.L. Castle Foundation pledged yesterday to double its giving to public schools over the next four years — with annual grants of $2.5 million to help push forward planned reforms — and urged other philanthropic organizations to also increase their support.

The $10 million will go to personnel development programs, including training for 36 principals who will be charged with turning around low-performing schools and a project to ensure that every teacher has a highly trained mentor by 2013.

In announcing the funding boost yesterday at Royal Elementary School, Castle Foundation President and Chief Executive Officer Mitch D’Olier said everyone — from the heads of large organizations to parents and students — needs to pitch in to improve Hawaii’s schools. He also said Race to the Top reforms under way bring new promise to a school system that has long lagged behind the rest of the nation.

“This is our opportunity,” D’Olier said. “This has got to be a team sport. Our foundation wants to encourage others in the community to create change.”

The Castle Foundation is one of several organizations that have for years helped fund improvement plans for Hawaii’s public education system. Over the past eight years, Castle has donated about $10 million.

The new funding will mean a big boost, though, to the total donated to Hawaii schools annually. In the 2009-10 school year, the DOE received $3.9 million in gifts (monetary or in-kind) of more than $500. That was up 25 percent from the year before.

At the news conference yesterday on the Castle donation, Gov. Neil Abercrombie said Hawaii will meet its big education reform goals only with a lot of help from the community.

Speaking to about 100 Royal School fifth-graders — members of the class of 2018 — who attended the news conference yesterday, Abercrombie said, “Everyone here is going to put their paddle in the water to help support you.”

The state’s education reforms are being pushed forward by a $75 million Race to the Top grant, which the U.S. Department of Education awarded Hawaii in August.

In its Race application, Hawaii pledged that by the time today’s fifth-graders graduate, all students will meet or exceed math and reading standards; every high school graduate will be ready for rigorous college courses or a competitive career; and Hawaii’s college-going rate will increase to 62 percent, the national median, from 51 percent.

DOE officials acknowledge Hawaii has a long way to go to meet those goals.

Last school year, 23 percent of Hawaii fourth-graders tested “below basic” in math on the National Assessment of Educational Progress, compared with 19 percent nationally.

Meanwhile, some 43 percent tested below basic on reading, compared with 34 percent nationally.