Irrigation and water for sugarcane
Case 1 A wet week on rainfed cane - 1
Pick the plot first Open a new chat and tap Plots (All) under the question box. Choose the plot you want advice for. ORTH then works from that plot’s crop, variety, soil and documents, and from the farm weather. For sugarcane Pick one plot of one variety and one cut. We picked Talhão 1: RB867515 on 12.64 ha of clay soil near Sertãozinho, planted in March 2023 as 18-month cane and harvested for the third time on 18 August 2026, green, with the straw left on the field. Every number below is for that plot. - 2
Start from the Irrigation button Pick the plot and tap Irrigation. ORTH offers questions such as this week’s schedule, a water-quality check, or turning the water requirement into runtime for your system. Tap one to ask it. For sugarcane Talhão 1 is rainfed, so the water questions are about drainage, timing and the vinasse that goes on after harvest. - 3
Ask for this week’s schedule We tapped Build this week’s irrigation schedule for this plot. ORTH said to add no water from 4 to 10 November. The plot is rainfed, and this week the priority is drainage and air in the root zone. Its table shows 55.1 mm of rain on 7 November and 9.3 mm on 8 November, with topsoil moisture rising to a reading of 34.6. On clay, more water would mean more waterlogging, less oxygen for the roots and more traffic damage. It rated the schedule four stars. - 4
Follow the field rules for the storm Before the storm, clear only the drains you can reach safely, without disturbing the stools. On 7 and 8 November keep the machines off the wet soil and watch the outlets and low spots from the field edge. On 9 and 10 November go in only if the clay carries you. If the cane wilts while the soil is still wet, look for compaction, poor aeration or root damage before you think of water. On 10 November review the plan with how long water stood and the moisture below the surface, because the topsoil reading alone may not show the whole root zone. Stay off saturated ground during the storm and protect the drain outlets from erosion. Case 2 Vinasse as salvage irrigation - 5
Work out the depth and the potassium We asked about 100 m³/ha of vinasse with a reel gun after the August 2027 harvest, on dry soil. That is 10 mm, or 10 L per m². On the 12.64 ha it is 1,264 m³, and with 2.0 kg K₂O per m³ from the lab it brings 200 kg K₂O/ha, 2,528 kg on the plot. ORTH noted that 1,264 m³ is the volume of vinasse. To know how much of it is water, you need the dry matter from the analysis. It rated the calculation five stars and the field operation three stars. - 6
Apply it once the harvest is over Apply it as soon as the harvest is over and the reel can move without damaging stools or leaving ruts, on dry but firm soil with no heavy rain coming. Then it moistens the stool and the upper roots, helps the buds start, softens the shock after harvest and carries potassium to the new roots. Ten millimetres is a salvage event: it helps around the stools without refilling a dry clay profile. Judge it by moist soil around the stools and better sprouting, rather than by the volume pumped. - 7
Watch the risks on clay The main risk is the gun putting water on faster than the clay takes it, so it runs off harvest lanes and wheel tracks into the low spots. Apply at the lowest practical intensity, check the spread with catch cans first, and stop if water flows between rows or stays in pools. Also watch for crusting, compaction if you drag or move the reel over wet ground, and salt or potassium build-up from overlaps and the end of each run. Do not add the planned potassium chloride on top. Get a full vinasse analysis with EC, sodium and SAR, keep the legal setbacks from drains, waterways and wells, and do not apply just before heavy rain.
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