Can Interseeding Spring Small Grains with Winter Wheat Increase Fall Forage Production?.

Roughly 50% of the six million wheat acres in Texas are grazed on any given year. Therefore, forage production in small grains systems is incredibly important and increasing fall forage production without impacting grain yield or spring forage production would benefit Texas wheat growers. Spring small grains do not require vernalization and growth is strictly based on heat units. If planted early in the fall, spring types will initiate reproductive growth and begin stem elongation and rapid biomass production unlike winter types that stay vegetative until spring. An experiment examining the impact of interseeding spring and winter small grains was conducted at College Station and McGregor, TX in 2013-14 and 2014-15. Three spring:winter interseeding ratios (0% spring, 25% spring, and 50% spring) were planted at four seeding rates (50, 75, 100, 125 lbs a^-1). In 2013-14, no differences were detected for forage production when spring wheat was interseeded with winter wheat over four harvests under a forage only system. However, total forage production decreased 0.25 t DM a^-1 over two cuts when interseeding 50% spring wheat under the dual-purpose system. In 2014-15, spring barley was interseeded with winter wheat and increased fall forage yield by 0.58 t DM a^-1 (483%) when interseeded at 50% of seed. Interseeding barley did reduce spring forage, but total forage production was still 0.43 t DM a^-1 greater than 100% winter wheat. Similar trends were observed at McGregor in 2014-15 as well. Seeding rate was not significant at either location. These results suggest interseeding spring types with winter small grains can enhance fall forage production for Texas wheat growers, though spring barley may be a better fit than spring wheat.