Use of technologies increases irrigated rice production in Tocantins

The State of Tocantins has increased the productive potential of the rice chain in recent years, becoming the third largest producer of irrigated rice nationally.

One of the reasons for this growth was the adoption of more sustainable technologies that generated an increase and improvement in the productive potential of rice, reinforcing the acquisition of more robust and disease-tolerant plants, better use of water and inputs, which was reflected in the entire production process in the region. .

The adoption of new rice varieties and other technologies are the result of a lot of work, research and technology transfer actions carried out by the Embrapa Arroz e Feijão technical team in conjunction with partner institutions in Tocantins and the rice production chain in the region.

The positive result in the agricultural balance of national production originated from the potential of the irrigated rice cultivated area in the State, which increased from 65 thousand/ha to 108 thousand/ha in recent years, with production of 750 thousand tons/year.   

The potential for cultivating irrigated rice also led to the emergence of new companies in the agro-industrial sector in the region, increasing the production system to make irrigated rice more competitive and meet the desires of the consumer market, mainly in the Central-West, North and Northeast regions of Brazil. country.

As an example of growth in rice production, in recent harvests we highlight five municipalities in the southwest of Tocantins that have placed regional production of tropical irrigated rice and their respective micro-regions on the national stage; In the 2018/2019 harvest, irrigated rice production in these municipalities totaled 110 establishments that planted rice in Formoso do Araguaia; 48 in Lagoa da Confusao; 12 in Dueré and 22 establishments in the Pium/Cristalândia region.

A total of 12.017 thousand hectares were planted in this harvest, and only in Cristalândia and Pium, municipalities that cover the region of the Pium, Água Verde and Riozinho rivers, rice production in the 2018/2019 harvest was 14.008 thousand hectares .

We highlight, below, the main technologies that were adopted by producers in the rice chain in Tocantins:

Rice varieties 

Among the various demands raised in the Tocantins region by the rice production chain in conjunction with the Embrapa technical team, with the Fundação Universidade do Tocantins – Unitins Agro, in addition to developing cultivars that are more tolerant to diseases, better productivity and more sustainable practical actions aimed at reducing production costs, improving the conservation and use of natural resources, especially water resources, and developing new varieties adapted to the soil and climate of Tocantins.

The fruit of this effort resulted in the development of three irrigated rice cultivars launched by the Embrapa breeding program team: BRS Pampeira, BRS Catiana and BRS A702 CL; Together, these cultivars represent 78% of all rice production in Tocantins, that is, of the 108 thousand hectares of area planted with irrigated rice in the 2018/2019 harvest, 84 thousand hectares were planted with just these cultivars; BRS Pampeira produced 53.550 ha (49%); BRS Catiana 27.195 ha (26%) and BRS A702 CL 3.168 ha (3%).

BRS Catiana obtained an average productivity of 6.386 kg/ha for producers in that region, reaching 9.900 kg/ha in the municipality of Lagoa da Confusao alone. The factor attributed to this results is mainly due to the reduction in the application of fungicides, especially to combat rice blast, considered the main rice disease in the State.

BRS Pampeira, under normal environmental and crop management conditions, obtains an industrial grain yield of more than 68% of polished whole grains; BRS Pampeira's focus is quality and quantity, its average productivity yields around 10 tons per hectare.  

Completing the trio of new rice cultivars in Tocantins, the BRS A702 CL was launched in 2018 in a partnership between Embrapa and BASF; This cultivar is characterized by allowing fewer herbicide applications, as it reduces from five to just two applications, at most. As a production indicator, the BRS A702 CL in the 2018/2019 harvest presented a productive potential of 3.168 kg/ha in an area of ​​7.650 hectares.

Alternative management to fires 

The presence of a large amount of post-harvest rice straw has led to operational difficulties in preparing the soil for the cultivation of species adapted to the highland system in succession to irrigated floodplain rice.

This is a very promising alternative for producers because the incorporation of rice straw into the soil facilitates its decomposition and avoids burning, a traditional practice used by producers that harms soil organic matter (SOM) and the atmosphere, due to the release of CO2 and other gases.

The use of the knife roller in the management of rice straw for planting soybeans in succession to the rice crop is another alternative that has provided environmental gains and agility in soil preparation.

Considering that for every ton of harvested rice grain there is a ton of straw that remains in the field, this residue that remains after harvesting becomes a problem for producers.

But with the use of the knife roller, it generates benefits for the soil and production, in addition to avoiding air pollution that causes other harm to health and the environment.

The incorporation of rice straw irrigated with a knife roller must be used immediately after harvesting, still with a layer of water; This makes it possible to prepare the soil in advance, saving time and reducing operations and fuel when cultivating soybeans in succession.

Use of rice ratoon 

Rice ratoon is the ability of plants to regenerate fertile tillers after cutting their stems at harvest. It is a viable alternative to increase grain productivity in irrigated rice production areas.

To be successful in ratoon cultivation, planning of the rice grain production system is necessary, which corresponds to the establishment of the main crop until the second harvest. Among the benefits of rice ratooning in grain production is the addition of value in the order of 20 to 30 bags/ha, which provides an increase in profitability for the producer, as production costs with this practice decrease, reaching even lower at 10 bags/ha. Another benefit of rice ratooning is the increase in production per unit of cultivated area, reducing the seasonality of the use of machines and implements.

In field conditions, cultural practices that promote rapid and uniform sprouting are especially important when used in ratoon cultivation, which helps plant performance, such as nitrogen fertilization, irrigation water management and phytosanitary treatments.

Nitrogen must be used in rice ratoon cultivation immediately after harvesting the main crop, as this will result in faster sprouting, with healthier tillers, increasing productivity and grain quality.

Water and nitrogen management 

Water management in irrigated rice cultivation comprises a set of procedures, all considered important, whether from an economic point of view or plant growth and development, and which involves both capture and distribution. In irrigated rice in Tocantins, it is important to consider the period of submersion of the soil, the height of the water depth and the drainage of the area.

Due to its agronomic characteristics, rice is among the most demanding crops in terms of water resources and this high requirement means that maintaining a water level on the soil surface generates a series of advantages for rice cultivation.

Just as an example, for irrigated rice cultivation, around 2000 L (2 m3) of water are needed by submersion to produce 1 kg of unpeeled grains, with rice being among the most demanding crops in terms of water resources.

The volume of water required to flood the soil is linked to the sum of water required to saturate the soil, form a layer, compensate for evapotranspiration and replace losses due to percolation and lateral flow.

The southeast of Tocantins is influenced by the tropical high-altitude climate and one of the lowest rainfall in the State (1200 mm); this means lower livestock yields and greater restrictions on rice farming.

This water management practice together with the application of nitrogen (N) to the crop brings an improvement in the local productive potential, as N provides a greater increase in grain productivity, especially in irrigated rice.

The first top dressing with nitrogen should preferably be carried out on dry soil, as long as the crop is flooded as quickly as possible (the maximum time between N application and crop flooding should be three days).

And top-dressing applications of nitrogen, after flooding the crop, must be carried out over the water depth, with the producer taking care to interrupt the circulation of water in the crop during this application period for at least three days. The important thing is for the producer to seek efficient alternative techniques for rice cultivation, aiming for better use of N by the plants.