SAO PAULO- Brazil's farmers had harvested 24% of the soy area through the end of last week, against 16% a week earlier and 9% in the same period last year, data from agribusiness consultancy showed AgRural on Monday.

Mato Grosso, the top grower, is the most advanced, with more than half of its area already harvested despite rainfall that tends to disrupt the work and reduce bean quality.

"With rains still very frequent, the harvest in Mato Grosso has advanced at intervals, with farmers rushing to get the soybeans out of the field before major quality problems occur," AgRural said.

There are complaints of grains with excess moisture in Rondonia and Minas Gerais, AgRural noted.

In Parana, average yields remain very low in the west and southwest areas, confirming losses due to lack of rain and heat.

As farmers reap their soy, planting of Brazil's second corn continues to progress, reaching 42% of the area in the Center-South, against 24% a week earlier and well ahead of the 11% in the same period of the year.

Second corn is sowed after soybeans are harvested in the same areas, and represent 70%-75% of overall output in a given year.

AgRural estimates soybean production in the 2021/22 crop in Brazil at 128.5 million tonnes and corn production at 110.9 million tonnes this season.

(Reporting by Ana Mano; editing by Jason Neely) ((ana.mano@thomsonreuters.com; Tel: +55-11-5644-7704; Mob: +55-119-4470-4529; Reuters Messaging: ana.mano.thomsonreuters.com@reuters.net))