Brazilian Soil Fertility Survey

Brazil lacks modern data for soil fertility surveys which can help the government, industry and crop consultants in their efforts to ameriolate soil chemical properties for adequate plant nutrition. IPNI Brazil has been involved in guiding the proccess for obtaining such surveys. The project was delineated in three phases. Phase 1 was a simple soil fertility survey from soil test results presently at IPNI Brazil database. Phase 2 is under development and will consist in a survey with laboratories running the ion exchange resin methodology and will concentrate in the State of Sao Paulo. Phase 3 will include the most important laboratories in the country. This project will be reported every 5 years.


14 Feb 2012

2011 Annual Interpretive Summary

Soil fertility surveys of specific countries or regions are an important tool to ascertain soil chemical properties for adequate crop nutrition. Due to a paucity of such information, the IPNI Brazil program led an effort to put together soil fertility information for Brazil. The plan is to complete this endeavor in three phases. This summary presents results of phase 1, which are also stored in IPNI Brazil database as Brazilian Soil Fertility Survey based on Soil Samples. For this phase, a total of 5,556 soil samples were collected but only 3,365 samples were used to interpret and classify different levels of nutrient sufficiency. For available P, three types of interpretation were necessary (exchange resin (P-Res); Mehlich 1 + clay content (P-Meh); or remaining P in solution (P-Rem)) with all three indicating response to P in the great majority of the samples (86%, 63% and 38% for P-Res, P-Meh and P-Rem, respectively). Simulation of collected data, considering that only soybean crop was grown in all areas, showed a requirement of about 1.5 to 2.0 million tons (Mt) of P2O5 for Brazil. For K, the survey showed that 44% of the soil samples had K levels that are considered very low or low in terms of K bioavailability. 78% of the samples presented levels indicating some kind of response to K. Simulations showed that about 2.2 Mt of K2O would be necessary considering recommendations from EMBRAPA (Brazilian Agronomic Agency) and soybean cropped in all areas. Among secondary nutrients, the survey showed that 76% of the soils would lead to S response, while among the micronutrients considered (Zn, Cu, Mn, and B), the survey indicated low levels of their bioavailability in the great majority of the samples. Interestingly, 98% of soil samples showed a clear trend to some kind of response to B. Phase 2 will deal with results of soil samples utilizing the ion exchange resin methodology, while phase 3 will try to include the highest possible number of soil samples from laboratories around the country. IPNI-44