Do you need to water in the seeds ?
No - it’s a winter growing season in SW Australia.
Just to clarify: all trials are aimed at replicating actual cropping methods in the area chosen for the trial. The only difference is that the plots are small, so seed, fertiliser etc. has to be measured precisely in order to be able to make valid comparisons of growth and yield. The GPS tracking, auto-steer, opening the cone to drop seed and so on keeps everything precisely located in an orderly layout.
It also saves a lot of walking measuring and pegging plots and ensuring square.
With farmers sowing crops in the hundreds and thousand of hectares, there is no way any irrigation occurs in such broadacre crops (the WA grain belt is maybe 300,000 sq km). Those crops (wheat, canola, barley, oats) are all winter-growing/spring maturing and hence are only grown in winter-rainfall areas in Australia under natural rainfall. Drought=no crop.
Those particular trials were, as I mentioned, canola. The seeds for each plot were in a very small envelope. Barely grams of seed are needed for a single plot (12 sq m). (Seeding rates for commercial canola crops are 2-3 kg per hectare - and a hectare is 10,000 sq m).
There has been good rain across the WA grain belt and the soil at that site had very good moisture. The press wheels ensure that the soil is pressed against the seed to ensure moisture can be absorbed for germination. The plants are then on their own, just like any commercial crop.