LONDON — The forecast for total world grain production in 2018-19 is forecast at 2,138 million tonnes, slightly lower than the previous year’s global output of 2,141 million tonnes, according to the International Grains Council.

The I.G.C.’s monthly Grain Market Report, released on May 30, said a larger corn harvest in 2018-19 nearly offset the poorer outturns of other grains, including a 29-million-tonne decline in wheat production.

“With smaller supplies and a sustained rise in consumption, grains stocks are forecast to tighten by 29 million tonnes to a three-year low of 617 million tonnes, with approximately half the drop in the major exporters and half in China,” the I.G.C. said.

The I.G.C. said an overall fall in grains trade in 2018-19 is anticipated as the 10th consecutive increase in corn shipments is outweighed by declines in wheat, barley and sorghum.

The I.G.C.’s projection for total grains production in 2019-20 is 2,177 million tonnes, modestly lower than the previous month’s projection but higher than the projected total for 2018-19.

With consumption growth predicted to outstrip the rise in supply, the third consecutive stock contraction is envisaged, to a four-season low of 602 million tonnes in 2019-20, according to the I.G.C.

“The retreat is entirely because of shrinking corn inventories, to their least in six years,” the I.G.C. said. “In contrast, after falling in the prior season, wheat stocks could rebound to a record level at the end of 2019-20.”

Grain trade in 2019-20 is forecast at 369 million tonnes, slightly exceeding the peak in 2017-18 on anticipated increased shipments of wheat and barley.

Reflecting an upgraded estimate for Brazil’s harvest, 2018-19 soybean output is raised by 1 million tonnes to 363 million, a 6% year-on-year gain and a new record, the I.G.C. said. However, due to a smaller figure for carry-ins, ending stocks are trimmed to 54 million tonnes, which is still the largest ever due to heavy accumulation of stocks in the United States.

With the United States and China locked in a trade war that has effectively halted soybean trade between the two countries, the I.G.C. noted that soybean production is projected to decline slightly in 2019-20.

“Prospects for (soybean) supply and demand in 2019-20 are uncertain,” the I.G.C. said. “Nevertheless, assuming larger outturns in the southern hemisphere help to compensate for a fall in the U.S., output is predicted just 5 million tonnes lower year on year and above average. Given the current policy and demand backdrop, outlooks for consumption and trade are highly tentative.”

Reflecting gains in key exporters, notably India as well as in sub-Saharan Africa world rice output in 2018-19 is seen at a record 500 million tonnes, the I.G.C. said.

The I.G.C. said ample availabilities and population growth should push consumption to 492 million tonnes, up from 487 million the previous year, while stocks are likely to accumulate on increases in China and India.

The Council noted that prospects for rice production in 2019-20 “are tentative but assumed growth in acreage in parts of Asia could boost production to a high of 504 million tonnes.”