Subsoil tillage improved the maize stalk lodging resistance under high planting density.

Lodging reduces maize yield and quality. The improvement in maize lodging resistance has proven to be instrumental in maximizing the yield potential of maize varieties under high-density planting. Tillage practices accommodate larger groups by enhancing soil conditions. This study aimed to elucidate the impact of subsoil tillage in reducing the maize stalk lodging rate. The maize cultivars Xianyu 335 (XY335) and Zhongdan2 (ZD2) were selected for field experiments including two tillage methods, shallow rotary (RT) and subsoil (SS), and two densities, 75,000 plants ha-1 (D1) and 105,000 plants ha-1 (D2), were set up to investigate and analyze the changes of maize lodging rate and the related indexes of lodging resistance under SS and RT conditions. The findings revealed that under high density, as compared to rotary tillage, SS tillage decreased the plant and ear height by 9.01-9.20 cm and 3.50-4.90 cm, respectively. The stalk dry matter accumulation was enhanced by 8.98%-24.98%, while stalk diameter between two and seven internodes increased by 0.47- 4.15 mm. Stalk cellulose increased by 11.83% -12.38%, hemicellulose increased by 6.7%-15.97%, and lignin increased by 9.86%-15.9%. The rind puncture and crushing strength improved by 3.11%-20.06% and 11.90%-27.07%, respectively. The bending strength increased by 6.25%-27.96% and the lodging rate decreased by 1.20%-6.04%. Yield increased by 7.58%-8.17%. At SS tillage when density increased, the index changes in ZD2 were mostly less than those in XY335. The rind penetration strength, bending strength, crushing strength, stalk diameter, and dry matter accumulation all had a negative correlation with the lodging rate. It suggested that SS tillage was beneficial to lodging resistance and, in combination with stalk lodging-resistant varieties, can effectively alleviate the problem of stalk lodging after increased planting density.

Regulation of tillage on grain matter accumulation in maize.

Introduction: To address issues related to shallow soil tillage, low soil nutrient content, and single tillage method in maize production in the Western Inner Mongolia Region, this study implemented various tillage and straw return techniques, including strip cultivation, subsoiling, deep tillage, no-tillage, straw incorporation with strip cultivation, straw incorporation with subsoiling, straw incorporation with deep tillage, and straw incorporation with no tillage, while using conventional shallow spinning by farmers as the control. Methods: We employed Xianyu 696 (XY696) and Ximeng 6 (XM6) as experimental materials to assess maize 100-grains weight, grain filling rate parameters, and grain nutrient quality. This investigation aimed to elucidate how tillage and straw return influence the accumulation of grain material in different maize varieties. Results and discussion: The results indicated that proper implementation of tillage and straw return had a significant impact on the 100-grains weight of both varieties. In comparison to CK (farmer's rotary rotation), the most notable rise in 100-grains weight was observed under the DPR treatment (straw incorporation with deep tillage), with a maximum increase of 4.84% for XY696 and 6.28% for XM6. The proper implementation of tillage and straw return in the field resulted in discernible differences in the stages of improving the grain filling rates of different maize varieties. Specifically, XY696 showed a predominant increase in the filling rate during the early stage (V1), while XM6 exhibited an increase in the filling rates during the middle and late stages (V2 and V3). In comparison to CK, V1 increased by 1.54% to 27.56% in XY696, and V2 and V3 increased by 0.41% to 10.42% in XM6 under various tillage and straw return practices. The proper implementation of tillage and straw return had a significant impact on the nutritional quality of the grains in each variety. In comparison to CK, the DPR treatment resulted in the most pronounced decrease in the soluble sugar content of grains by 25.43% and the greatest increase in the crude fat content of grains by 9.67%. Conclusion: Ultimately, the proper implementation of soil tillage and straw return facilitated an increase in grain crude fat content and significantly boosted grain weight by improving the grouting rate parameters at all stages for various maize varieties. Additionally, the utilization of DPR treatment proved to be more effective. Overall, DPR is the most promising strategy to improve maize yield and the nutritional quality of grain in the long term in the Western Inner Mongolia Region.

Effect of Subsoiling on the Nutritional Quality of Grains of Maize Hybrids of Different Eras.

To achieve high maize (Zea mays L.) yields and quality grain, it is necessary to develop stress-resistant cultivars and related cultivation practices, aiming to maximize efficiency. Thus, our objectives were (i) to investigate the impact of tillage practices and maize hybrids (which have improved over time) on yield and its components, and (ii) to characterize the response pattern of maize hybrid grain nutrient quality components to subsoiling. To achieve this, we conducted field trials with five maize hybrids from different eras under two tillage practices: rotary tillage and subsoiling. We compared grain yield, nutritional quality, and other indicators across different tillage conditions from the 1970s to the 2010s. The main results of this study are as follows: under rotary tillage conditions, the 2010s hybrid (DH618) significantly increased yields (9.37-55.89%) compared to hybrids from the 1970s-2000s. After subsoiling, the physiologically mature grains of all hybrids exhibited minimal changes in crude protein and fat content, while there was a significant reduction in the total soluble sugar content of the grains. After subsoiling, there was a substantial 8.14 to 12.79 percent increase in total starch accumulation in the grain for all hybrids during the period of 47-75 days post-anthesis. Furthermore, during the period of 47-75 days after anthesis, the consumption of grain crude protein significantly contributed to the accumulation of total starch in the grains. Ultimately, subsoiling significantly increased the yield of each hybrid and enhanced the total grain starch content at physiological maturity of all hybrids, with the 2010s hybrid (DH618) performing exceptionally well.

Improving maize quality from mechanical grain harvesting by matching maize varieties with accumulated temperature in northeast China.

BACKGROUND: Global warming has led to methods of planting late-maturing maize varieties in northeast China that have hindered the development of physiological maturity (PM) at harvest and the use of mechanical grain harvesting (MGH). Under these conditions it is difficult to balance the drying characteristics of maize varieties and to make full use of accumulated temperature resources in such a way as to reduce grain moisture content (GMC) at harvest. RESULTS: The effective accumulated temperature (AcT) and the drying rates of different varieties vary. In northeast China, with a GMC of 25%, the growth periods of a fast-drying variety (FDV) and a slow-drying variety (SDV) were 114-192 days and 110-188 days respectively. After PM, the FDV needed 47 days and the SDV needed 51 days to reduce the GMC to be ready for MGH. Harvested with a GMC of 20%, the growth period for the FDV was 97-175 days and for the SDV it was 90-171 days. After PM, the FDV required 64 days and the SDV needed 70 days to reduce the GMC to be ready for MGH. CONCLUSION: Matching cultivars with AcT can help farmers to choose suitable varieties. Promoting MGH may boost maize production, thus ensuring China's food security. © 2023 Society of Chemical Industry.

Metagenomics study to compare the taxonomic composition and metabolism of a lignocellulolytic microbial consortium cultured in different carbon conditions.

A lignocellulolytic microbial consortium holds promise for the in situ biodegradation of crop straw and the comprehensive and effective utilization of agricultural waste. In this study, we applied metagenomics technology to comprehensively explore the metabolic functional potential and taxonomic diversity of the microbial consortia CS (cultured on corn stover) and FP (cultured on filter paper). Analyses of the data on metagenomics taxonomic affiliations revealed considerable differences in the taxonomic composition and carbohydrate-active enzymes profile of the microbial consortia CS and FP. Pseudomonas, Dysgonomonas and Sphingobacterium in CS and Cellvibrio and Pseudomonas in FP had a much wider distribution of lignocellulose degradative ability. The genes for more lignocellulose degradative enzymes were detected when the relatively simple substrate filter paper was used as the carbon source. Clusters of Orthologous Groups (COG) and Kyoto Encyclopedia of Genes and Genomes (KEGG) annotation analyses revealed considerable levels of similarity, and carbohydrate metabolic and amino acid metabolic pathways were the most enriched in CS and FP, respectively. The mechanism used by the two microbial consortia to degrade lignocellulose was similar, but the annotation of quantity of genes indicated that they are diverse and vary greatly. These data underlie the interactions between microorganisms and the synergism of enzymes during the degradative process of lignocellulose under different substrates and suggest the development of potential microbial resources.

Regulation of subsoiling tillage on the grain filling characteristics of maize varieties from different eras.

Grain filling is the key stage for achieving high grain yield. Subsoiling tillage, as an effective conservation tillage, has been widely used in the maize planting region of China. This study was conducted to explore the effects of subsoiling on the grain filling characteristics of maize varieties of different eras. Five typical maize varieties from different eras (1970s, 1980s, 1990s, 2000s and 2010s) were used as experimental materials with two tillage modalities (rotation tillage and subsoiling tillage). The characteristic parameters (Tmax: the time when the maximum grouting rate was reached, Wmax: the grain weight at the maximum filling rate, Rmax: the maximum grouting rate, P: the active grouting stage, Gmean: the average grouting rate; A: the ultimate growth mass) and rate parameters (T1: the grain filling duration of the gradually increasing stage, V1: the average grain filling rate of the gradually increasing stage, T2: he grain filling duration of the rapidly increasing stage, V2: the average grain filling rate of the rapidly increasing stage, T3: the grain filling duration of the slowly increasing stage, V3: the average grain filling rate of the slowly increasing stage) of grain filling of two tillage modalities were analyzed and compared. The results showed that the filling parameters closely correlated with the 100-kernel weight were significantly different among varieties from different eras, and the grain filling parameters of the 2010s variety were better than those of the other varieties, the P and Tmax prolonged by 4.06-19.25%, 5.88-27.53% respectively, the Rmax and Gmean improved by 5.68-14.81%, 4.76-12.82% and the Wmax increased by 10.14-32.58%. Moreover, the 2010s variety helped the V2 and V3 increase by 6.49-13.89%, 4.55-15.00%. In compared with rotation tillage, the grain yield of maize varieties from different eras increased by 4.28-7.15% under the subsoiling condition, while the 100-kernel weight increased by 3.53-5.06%. Under the same contrast conditions, subsoiling improved the Rmax, Wmax and Gmean by 1.23-4.86%, 4.01-5.96%, 0.25-2.50% respectively, delayed the Tmax by 4.04-5.80% and extended the P by 1.19-4.03%. These differences were major reasons for the significant increases in 100-kernel dry weight under the subsoiling condition. Moreover, subsoiling enhanced the V2 and V3 by 0.70-4.29%, 0.00-2.44%. The duration of each filling stage and filling rate of maize varieties from different eras showed different responses to subsoiling. Under the subsoiling condition, the average filling rate of the 1970-2010s varieties were improved by 1.18%, 0.34%, 0.57%, 1.57% and 2.69%. In the rapidly increasing period, the grain filling rate parameters of the 2010s variety were more sensitive to subsoiling than those of the other varieties. The rapidly increasing and slowly increasing period are the key period of grain filling. Since the 2010s variety and subsoiling all improve the grain filling rate parameters of two periods, we suggest that should select the variety with higher grain filling rate in the rapidly increasing and slowly increasing period, and combine subsoiling measures to improve the grain filling characteristic parameters of maize in production, so as to achieve the purpose of increasing 100 grain weight and yield.