Uniformity Detection for Straws Based on Overlapping Region Analysis

Nowadays, the advanced comprehensive utilization and the complete prohibition of burning fully covered straws in croplands have become increasingly important in agriculture engineering. As a kind of direct straw-mulching method in China, conservation tillage with straw smashing is an effective method to reduce pollution and enhance fertility. In view of the high straw-returning yields, complicated manual operation, and the poor performance of straw detection with machine vision, this study introduces a novel form of uniformity detection for straws based on overlapping region analysis. An image-processing technology using a novel overlapping region analysis was proposed to overcome the inefficiency and low precision resulting from the manual identification of the straw uniformity. In this study, the debris in the gray map was removed according to region characteristics. Through using morphological theory with overlapping region analysis in low-density cases, straws of appropriate length can be identified and then uniformity detection can be accomplished. Compared with traditional threshold segmentation methods, the advantages of an accurate identification, fast operation, and high efficiency contribute to the better performance of the innovative overlapping region analysis. Finally, the proposed algorithm was verified through detecting the uniformity in low-density cases, with an average accuracy rate of 97.69%, providing a novel image recognition solution for automatic straw-mulching systems.

Straw Mulching with Minimum Tillage Is the Best Method Suitable for Straw Application under Mechanical Grain Harvesting

Mechanical grain harvesting is a crop production development direction. However, the residue management methods suitable for mechanical grain harvesting have been not established. In order to study the effect of residue management modes on maize yield formation and explore the best residue management methods for mechanical grain harvesting, four crop field surveys were carried out in Southwest China. Crops were mechanically harvested, and the residues were shredded and returned to the field using various straw application methods including straw deep burial with plowing (SDBP), straw shallow burial with rotary tillage (SSBRT), and straw mulching with minimum tillage (SMMT). The first-season rape residues were returned to the field, and the second-season maize yield under SDBP and SSBRT was significantly higher than that under SMMT. However, with the increase in rounds of residue application, compared with SDBP and SSBRT, SMMT continuously increased the soil moisture content in the 0–30 cm soil layer at the early stage of maize growth, increased the soil alkaline-hydrolyzed nitrogen content in the 0–20 cm and 40–60 cm layers, and reduced the soil compaction under 40 cm layer, which were more conducive to the root system growth. Maize yield with the SMMT increased by 5.4% compared with that of the previous season, while the yields with SDBP and SSBRT decreased by 16.7% and 12.7%, respectively, compared with those of the previous season. In conclusion, it is recommended to employ the SMMT method during crop mechanical harvesting, which is of great significance to improve soil quality and increase maize grain yield.

Effect of residue and nutrient management on productivity, nutrient uptake, economics and greenhouse gas emission of rice in intensified rice-based cropping systems

A long-term field experiment was conducted at Institute research farm, ICAR-National Rice Research Institute, Cuttack, Odisha since 2012-13. The experiment was conducted in a split plot design involving two cropping systems i.e., rice-maize-cowpea (R-M-C) and rice-groundnut-cowpea (R-G-C) covering three crops in three seasons i.e., kharif, rabi and summer, respectively in main plots and five nutrient management treatments i.e., control control - control (C-C-C), RDF-RDF - RDF (R-R-R), Residue Incorporation (RI) +75% of RDF-RDF - RDF (RI+R75-R-R), RI+ 75 % of RDF-Straw Mulching (SM) + RDF - RDF (RI+R75-SM+R-R) and RI+75 % of RDF - SM+RDF - 50 % of RDF (RI+R75-SM+R-R50) in sub-plots; where control indicates no fertilizer application to each crop of the system, RDF indicates recommended dose of fertilizers for respective crops, RI indicates cowpea residue incorporation in succeeding rice crop before transplanting and SM indicates rice straw mulching @ 6 t ha-1 in succeeding groundnut and maize. Significant improvement in growth parameters of rice i.e., plant height, tillers plant-1, leaf area index, dry matter accumulation, yield i.e., grain yield, straw yield, harvest index, nutrient uptake, economic gain i.e., gross return, net return and B:C ratio, CH4 flux in cowpea residue incorporated treatments than the residue removal treatments. Cowpea residue incorporation with 75% of recommended dose of fertilizer to rice followed by straw mulching with recommended dose of fertilizer to rabi season crops i.e., maize and groundnut and recommended dose of fertilizer to summer season crops i.e., RI+R75-SM+R-R recorded 10.2% higher number of tillers hill-1, 17.1% higher LAI, 10.9% higher DMA, 8.5% higher panicles m-2 and 8.8% higher filled grains panicle-1 than recommended dose of fertilization to each crop i.e., R-R-R. RI+R75-SM + R-R also recorded 11.3% higher grain yield, 9.7% higher straw yield, 13.7% higher N uptake, 15.8% higher P uptake, 11.9% higher K uptake, 11.3% higher gross return, 15.1% higher net return and 25.6% less N2O emission than recommended dose of fertilization to each crop i.e., R-R-R. Cowpea residue incorporation with 25% reduction in RDF, straw mulching with RDF to rabi season crops i.e., maize and groundnut and RDF to summer season crops (RI+R75-SM+R-R) however recorded at par growth, yield, nutrient uptake and economic return to that of RI+R75-SM+R-R50. Thus, RI+R75-SM+R-R50 could be useful in achieving higher productivity and profitability from rice in an intensified rice-based cropping system.