Machine learning approaches for crop yield prediction and nitrogen status estimation in precision agriculture: A review

An overview and comparison of machine-learning techniques for classification purposes in digital soil mapping

Digital soil mapping algorithms and covariates for soil organic carbon mapping and their implications: A review

Foreknowledge about sugarcane crop size can help industry members make more informed decisions. There exists many different combinations of climate variables, seasonal climate prediction indices, and crop model outputs that could prove useful in explaining sugarcane crop size. A data mining method like random forests can cope with generating a prediction model when the search space of predictor variables is large. Research that has investigated the accuracy of random forests to explain annual variation in sugarcane productivity and the suitability of predictor variables generated from crop models coupled with observed climate and seasonal climate prediction indices is limited. Simulated biomass from the APSIM (Agricultural Production Systems sIMulator) sugarcane crop model, seasonal climate prediction indices and observed rainfall, maximum and minimum temperature, and radiation were supplied as inputs to a random forest classifier and a random forest regression model to explain annual variation in regional sugarcane yields at Tully, in northeastern Australia. Prediction models were generated on 1 September in the year before harvest, and then on 1 January and 1 March in the year of harvest, which typically runs from June to November. Our results indicated that in 86.36 % of years, it was possible to determine as early as September in the year before harvest if production would be above the median. This accuracy improved to 95.45 % by January in the year of harvest. The R-squared of the random forest regression model gradually improved from 66.76 to 79.21 % from September in the year before harvest through to March in the same year of harvest. All three sets of variables—(i) simulated biomass indices, (ii) observed climate, and (iii) seasonal climate prediction indices—were typically featured in the models at various stages. Better crop predictions allows farmers to improve their nitrogen management to meet the demands of the new crop, mill managers could better plan the mill’s labor requirements and maintenance scheduling activities, and marketers can more confidently manage the forward sale and storage of the crop. Hence, accurate yield forecasts can improve industry sustainability by delivering better environmental and economic outcomes.

/pdf/accurate-prediction-of-sugarcane-yield-using-a-random-forest-zdnguae140.pdf

Accurate prediction of sugarcane yield using a random forest algorithm

Digital mapping of soil carbon fractions with machine learning

Digital mapping of soil organic matter for rubber plantation at regional scale: An application of random forest plus residuals kriging approach

A robust method to estimate foliar phosphorus of rubber trees with hyperspectral reflectance

The invention discloses a water-retaining and slowly-release compound fertilizer and a preparation method thereof The water-retaining and slowly-release compound fertilizer is prepared from the following components in parts by weight: 60-75 parts of chemical fertilizers, 1-6 parts of a water-retaining agent and 19-39 parts of filler, wherein the chemical fertilizers are at least two of a nitrogen source fertilizer, a phosphorus source fertilizer and a potassium source fertilizer; the water-retaining agent is at least one of polyacrylamide, sodium polyacrylate and sodium carboxymethylcellulose; the filler is at least one of bentonite, attapulgite, kaolin, talcum powder and gypsum powder The preparation method comprises the following steps: 1) mixing the chemical fertilizers, the water-retaining agent and the filler to obtain a mixture; 2) adding water in the mixture and granulating; stopping adding water when small particles are formed, then adding the filler powder, granulating, and finally drying to obtain the water-retaining and slowly-release compound fertilizer The water-retaining and slowly-release compound fertilizer disclosed by the invention has a water-retaining property and a slowly-release property, and is capable of reinforcing the water-retaining and water-holding capacities of soil, increasing the utilization rate of water resources, increasing utilization rate of the fertilizers, reducing nutrient loss, resisting drought, and reducing the pollution of fertilization to an ecological environment; the preparation method is simple and easy to process and produce

Water-retaining and slowly-release compound fertilizer and preparation method thereof

The invention discloses a double-layer coated fertilizer and a preparation method thereof. The double-layer coated fertilizer is composed of a core fertilizer, and an inner-layer coating material and an outer-layer coating material both covering the core fertilizer; the inner-layer coating material is microcrystalline wax; the outer-layer coating material comprises a water-retaining agent and a coating agent; the mass ratio of the core fertilizer, the inner-layer coating material and the outer-layer coating material is 100:(0.5-2):(3-20); the mass ratio of the water-retaining agent to the coating agent is 100:(5-30). The preparation method comprises the following steps: adding the core fertilizer and the inner-layer coating material to a coating machine, blasting air and heating until the inner-layer coating material is melted to cover the core fertilizer, thereby obtaining the fertilizer covered with the inner-layer coating material; 2) covering the fertilizer covered with the inner-layer coating material with the outer-layer coating material for at least once, thereby obtaining the double-layer coated fertilizer. The double-layer coated fertilizer has better controlled release and water retaining effects; the preparation method is simple; the coating agent is good in dissolving effect, and advantageous for coating; the production method is suitable for batch production.

Double-layer coated fertilizer and preparation method thereof

The invention discloses controlled release fertilizer rods and a preparing method thereof. The controlled release fertilizer rods are prepared from 2-6 parts of water-soluble water-retaining agents, 15-35 parts of nitrogen fertilizer, 10-25 parts of phosphate fertilizer, 10-30 parts of potassium fertilizer, 5-10 parts of medium trace element fertilizer and 10-40 parts of filler. The preparing method of the controlled release fertilizer rods comprises the following steps that the phosphate fertilizer, the nitrogen fertilizer, the potassium fertilizer and the medium trace element fertilizer are weighed according to the dosage, are smashed respectively and pass through a 20-mesh screen, the water-soluble water-retaining agents, the filler, the smashed nitrogen fertilizer, the smashed phosphate fertilizer, the smashed potassium fertilizer and the smashed medium trace element fertilizer are added into a chufa type coating machine together, a certain amount of water is sprayed through atomization pressure, and the materials are evenly mixed, added into a fertilizer forming machine and squeezed into the controlled release fertilizer rods. After the controlled release fertilizer rods are applied into soil, the fertilizer rods dissolve slowly, nutrients can be easily absorbed by crops, the nutrient supply time is prolonged, and the utilization rate of fertilizer can be effectively increased; in addition, the production process is simple, quality can be adjusted as needed, fertilizer application operation is easy and convenient, the controlled release fertilizer rods can be easily accepted by peasants and are suitable for being applied to trees with economic value and fruit trees in mountainous areas, and significant social benefits and wide application and popularization prospects are achieved.

Guo Pengtao

Papers

Digital mapping of soil organic matter for rubber plantation at regional scale: An application of random forest plus residuals kriging approach

A robust method to estimate foliar phosphorus of rubber trees with hyperspectral reflectance

Water-retaining and slowly-release compound fertilizer and preparation method thereof

Double-layer coated fertilizer and preparation method thereof

Controlled release fertilizer rods and preparing method thereof