Validation of Soil-Test-Based Phosphorus and Potassium Fertilizer Recommendations for Irrigated Soybean

2019 ◽  
Vol 83 (3) ◽  
pp. 825-837 ◽  
Author(s):  
Matthew S. Fryer ◽  
Nathan A. Slaton ◽  
Trenton L. Roberts ◽  
W. Jeremy Ross
2019 ◽  
Vol 111 (5) ◽  
pp. 2523-2535 ◽  
Author(s):  
Matthew S. Fryer ◽  
Nathan A. Slaton ◽  
Trenton L. Roberts ◽  
Jarrod T. Hardke ◽  
Richard J. Norman

Soil Research ◽  
1968 ◽  
Vol 6 (1) ◽  
pp. 93 ◽  
Author(s):  
JD Colwell

The estimation of the phosphorus and potassium fertilizer requirements of wheat and potatoes from soil test calibration equations is described. The procedure is based on the estimation of yield response to fertilizer at the site represented by the soil test and the application of economic principles to the function thus established. Soil testing may be justified on the basis of statistical tests of significance on these estimates. Since, however, testing can be expensive it should also be justified on economic grounds, such as by comparison of the profit obtained from the use of soil test estimates of fertilizer requirement with the profit from the use of some alternative estimate of fertilizer requirement. A preliminary evaluation may be made from a comparison of profits from soil test and average regional estimates of fertilizer requirement, using the calibration equation for the estimation of profits at different soil test levels. This method of evaluation separates the benefit due to testing from that due to the application of fertilizers. It is shown by this procedure that a soil test for the phosphorus fertilizing of wheat and for potassium fertilizing of potatoes in southern Ontario is worth while, given sufficient diversity of nutrient level within the region.


Author(s):  
M. A. Hossain ◽  
M. N. A. Siddique

The recent progression and Green Revolution (approx. between the 1990s-2010s) in agriculture of Bangladesh resulted in an increase of total production despite yield-gap to ensure food security. But agriculture in Bangladesh is still backed-up by higher use of inputs (agrochemicals-fertilizers, pesticides; modern varieties, irrigation etc.) and inversion tillage. This conventional agrochemical-based smallholder agriculture may lead to soil and environmental degradation, soil acidification, and a decline in soil fertility. Therefore, it is significant to optimize input application in intensive agriculture, especially fertilizers. This paper introduces the potential online facilities of generating online fertilizer recommendations for smallholder farmers in Bangladesh to ensure proper usage of fertilizers and enable sustainable agricultural production. We also highlighted how the usage of fertilizers increased with an increase in total production over time. But the sustainability of production in the years to come still remain challenging. With the aim of sustainable crop production, reduction in the misuse of fertilizers and reduction of input cost by optimizing the present pattern of excessive fertilizer application, the Soil Resource Development Institute (SRDI) provides location-specific fertilizer recommendation through both the manual and soil test based interpretation of plant nutrients: soil database in Upzazila Nirdeshika and static laboratory soil analysis. Recently, SRDI developed web-based software named Online Fertilizer Recommendation System (OFRS). The system is capable of generating location-specific fertilizer recommendations for selected crops by analyzing the national soil database developed by this governmental institute. The software requires farmer field location, respective soil and land type, and crop type and variety information to generate crop-specific instant fertilizer recommendation. It was observed that by using fertilizer according to the recommended dose calculated on the basis of soil test values, farmers could harvest approx. 7-22% higher yield of different crops over usual farmers practice. If this system can be popularized and disseminated by effective agricultural extension, this would immensely contribute to the promotion of precision agriculture, input cost reduction and it would certainly enable us to optimize fertilizer application by the smallholder farmers in Bangladesh.


2020 ◽  
Vol 25 (2) ◽  
pp. 93
Author(s):  
Muhammad Hatta

The recommendations of Phosphorus (P) and Potassium (K) fertilization for rice are still not site-specific yet due to a lack of required soil data information.  The P and K status of the paddy fields that provide information on the low, medium, and high P and K nutrient status are very useful for determining recommended the site-specific fertilizer in the the district area. The purpose of the research was to determine the site-specific fertilizer recommendation for paddy field based on their P and K status. This research was based on the field survey and the soil analysis in the laboratory. The soil samples were taken using a grid system, and the P and K levels were assessed by using a 25% HCl extraction. Soil samples were taken in a composite manner on all paddy fields in which their status have been identified. The composite soil samples were determined from 10 - 15 individual samples (sub-samples) with a sampling distance of each sub-sample of 25-50 m in the field.  The soil samples were taken in the overlay with a depth of 0-20 cm. Taking sub-samples were done by a diagonal or a zigzag method according to the conditions of paddy fields. The results of the study presented that the nutrient status of P and K and the fertilizer recommendations in paddy fields for rice plants located in 9 sub-districts in Mempawah Dsitrict had shown that nutrient status of P, on average, were from moderate to high levels, meanwhile, the nutrient status of K was from low to high levels. Recommendations for fertilizing rice fields in several sub-districts in Mempawah Regency are mostly 150 kg NPK (15:15:15) ha-1, 200 kg Urea ha-1 and 25 kg KCl ha-1.


2017 ◽  
Vol 12 (42) ◽  
pp. 3112-3119
Author(s):  
B. Cuvaca Ivan ◽  
S. Eash Neal ◽  
M. Lambert Dayton ◽  
R. Walker Forbes ◽  
Rustrick William

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