Prediction of soil-rice selenium transfer by machine learning
摘要
Selenium(Se) is an essential micronutrient for health and rice is the main source of Se for human body. However, rice grown in Se rich soil may not necessarily be Se rich, and rice grown in non Se rich soil may also be Se rich. Therefore, the purpose of this paper is to develop a machine learning algorithm to predict Se in rice and provide a basis for the division of Se-rich land.
Methods30095 topsoil samples and 927 pairs of soil-rice samples were collected in Fujian province, China. The random forest(RF) and back-propagation artificial neural network(BP-ANN) model were selected and optimized. Based on the optimal hyperparameters, the two models were trained respectively, and the better one was selected by the reverse verification of the training results.
ResultsThe optimized results of the BP-ANN indicated that the RMSE value was the lowest when there were 6 neurons in the first hidden layer and 6 neurons in the second hidden layer, and the RMSE value was the lowest when the ntree and mtry values were 30 and 2 respectively in RF model. Based on the optimal hyperparameter, the R of RF(R = 0.93) was higher than BP-ANN(R = 0.81).
ConclusionThe RF had the better performance than BP-ANN. SOM, P, pH and MAP were the main factors affecting Se content in rice through feature importance analysis.