New zoning of grain sorghum and millet guides agricultural production

The Official Gazette of the Union was published this Friday, October 23, the Ordinances of 303 a 350 with the Agricultural Climate Risk Zoning (Zarc), crop year 2020/2021, for the cultivation of grain sorghum and millet.

Zarc aims to indicate periods of lower risk for planting, reducing the likelihood of problems related to undesirable weather events occurring. In this way, it allows the producer to identify the best time to plant, taking into account the region of the country, the culture and the different types of soil.

The current agricultural climate risk zoning for sorghum has undergone major changes. “A fundamental change was the generation of Zarc specific to grain sorghum”, says researcher Daniel Pereira Guimarães, from Embrapa Milho e Sorgo. From 2021 onwards, Zarc will be made available for forage sorghum, which will be mainly aimed at the manufacture of forage for animal production, both in the form of grazing and silage.

Another important innovation in zoning studies refers to the use of crop coefficients, which are indicators of water demand throughout the growth phases, incorporating drought tolerance characteristics and allowing risk areas to be coherent with the zoning systems. production used in different Brazilian regions.

The inclusion of appropriate temperature ranges for crop development helps to avoid low productivity in places with low temperatures, due to the thermal sensitivity of grain sorghum and millet. “The use of excess water as a limiting factor for the growth of grain sorghum and millet contributes to the risk of losses caused by intolerance to soil waterlogging and to preventing cultivation in conditions conducive to the emergence of diseases, also favoring greater longevity of the cultivars launched on the seed market”, explains Guimarães, who is responsible for Zarc for the two crops in Brazil. 

As they are crops that present characteristics of drought tolerance and good adaptability, all Brazilian States were covered by Zarc ordinances for sorghum and millet. 

Zarc

Farmers who follow Zarc's recommendations are less subject to climate risks and may benefit from the Agricultural Activity Guarantee Program (Proagro) and the Rural Insurance Premium Subsidy Program (PSR). In these two programs it is mandatory to follow Zarc's recommendations.

Many financial agents only allow access to rural credit for crops in zoned areas and for planting cultivars indicated in zoning ordinances. 

Right Planting App

Rural producers and other agribusiness agents can access Zarc's official information via tablets and smartphones in a more practical way, facilitating guidance on the federal government's agricultural policy programs. The Zarc Plantio Certo mobile application, developed by Embrapa Informática Agropecuária (Campinas/SP), is available in application stores: iOS e Android.  

Sorghum and Millet

Sorghum (Bicolor sorghum (L.) Moench), of African origin, is the fifth most cultivated cereal in the world and is adapted to conditions of high temperatures and low water availability.

According to Guimarães, this cultivation plays an important role in the expansion of grain production in the country, due to its adaptability to semi-arid regions and the possibility of producing a second crop in areas unsuitable for the traditional soybean-corn combination.

Another characteristic that favors the expansion of sorghum, described by the researcher, is second-crop cultivation due to the reduction in cultivation windows. This reduction is caused by climate variations or the use of late-cycle materials in the first harvest, as a strategy to mitigate losses due to dry spells. “For comparative purposes, sorghum requires 330 liters of water to produce 1 kg of dry matter, while corn and wheat require 370 and 500 liters of water for this function, respectively”, says Guimarães.

“In addition to the adjustment of this crop to Brazilian conditions, several factors contribute to the expansion of sorghum cultivation in the country, such as broad adaptation to climatic conditions, lower water requirements, tolerance to the presence of aluminum in acidic soils, fully mechanized cultivation and low production cost. Sorghum also contributes to the reduction of nematode infestation in the soil, produces high-quality protein and toxin-free feed and helps in the formation of soil protection straw”, points out Guimarães.

The millet (pennisetum glaucum (L.) R.BR) is the sixth most cultivated cereal on the planet. “The cultivation of millet is related to soil protection and animal feed and today it occupies 4 million hectares as a cover crop, in the Cerrados region alone, making an extraordinary contribution to the sustainability of tropical agriculture”, says Guimarães.

“The high incidence of solar radiation during dry periods interferes with the conservation of water in the soil, the mineralization of organic matter, the loss of nutrients due to the action of winds, the formation of heat islands, the increase in susceptibility to erosion, the reduction of soil biota and other environmental damage”, says the researcher.

Another relevant factor is the high C/N (carbon/nitrogen) ratio of millet straw, which guarantees greater soil protection and contributes to the suppression of weeds, reducing the use of herbicides in farming. “The deep root system improves the soil profile, facilitates water infiltration and soil decompression, in addition to recycling nutrients from deeper layers. Millet roots are poor hosts and act to reduce nematode infestation in the soil”, explains Guimarães.

“Production costs are low, and implementation can be done by overseeding, including by plane, ensuring the best use of soil moisture. Its use as a forage-producing plant for animal feed brings comparative advantages due to low nutritional requirements, adaptation to sandy textured soils, high tolerance to drought and high temperatures, direct grazing or in the form of silage and high nutritional quality”, points out Guimarães.