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 tillage and fertilizer doses on growth and growth indices of soybean (Glycine max L.) under conservation tillage systems

A field experiment was conducted during kharif season of 2019 at the Research Farm, Department of Agronomy, CSKHPKV, Palampur to study the effect of tillage and fertilizer doses on growth and growth indices of soybean under conservation tillage systems. The experiment consisted of twelve treatment combinations which included three tillage systems minimum tillage, minimum tillage with crop residue and conventional tillage and four fertility levels viz; 25 % recommended dose of fertilizer (RDF) , 50 %(RDF) , 75 % RDF and 100% RDF and which were tested in split plot design with tillage system in main plots and fertility levels in sub plots.The soil texture of experimental site was silty clay loam. Minimum tillage along with crop residues (T2)recorded significantly taller plants and higher dry matter accumulation followed by conventional tillage. Absolute growth rate, crop growth rate, dry matter efficiency, relative growth rate and unit area efficiency were significantly higher with minimum tillage + crop residue treatment. Application of 100 % followed by 75 % recommended dose of fertilizer resulted in significantly higher growth parameters and growth indices.

Grain Yield and Nitrogen Uptake of Maize (Zea mays L.) as Affected by Soil Management Practices and Their Interaction on Cambisols and Chernozem

Although numerous factors contribute to wide yield gaps, low external inputs, particularly N, and poor cropping practices such as soil tillage and monocropping are among the major factors affecting low maize production. In view of this, field experiments were implemented on two sites with Cambisols and Chernozem soil types in two consecutive years to evaluate the impacts of different soil management practices on the grain yield and quality, nitrogen uptake, and selected soil properties. A three-factor experiment was arranged as a split-split plot arrangement randomized complete block design with three replications. The minimum tillage (MT) and conventional tillage (CT) were used as the main plot, haricot bean-maize rotation and maize monocropping were used as the subplot, and four levels of nitrogen fertilization (control, 20 t ha-1 compost, 46 kg N ha−1 + 10 t ha−1 compost, and 92 kg N ha−1) were used as the sub-subplot. Analysis of variance showed that soil management practices were significantly affecting grain yield, N-uptake, and soil properties. In sites, the conventional tillage and rotation system increased the grain yield and N-uptake in contrast to the minimum tillage and monocropping, respectively. Similarly, nitrogen evidently affected the grain yield, N-uptake, and selected soil properties. However, tillage methods differed in their effects on soil chemical properties; soil organic carbon and total nitrogen concentrations were improved through MT compared to CT. Grain yield was significantly associated with NDVI, grain N-content, and N-uptake. Therefore, a CT plus haricot bean-maize rotation system with the addition of solely 92 kg N ha−1 and integrated 46 kg N ha−1 + 10 t compost ha−1 could be recommended for Hawassa Zuria (Cambisols) and Meskan (Chernozem) districts, respectively. However, in order to ensure sustainable maize production in the investigated areas, an integrated N treatment with MT and a rotation system may be recommended, which could improve soil properties.

Soil fertility and corn yield changes depending on the tillage system

Tillage system is one of the factors that influences crop yield. The aim of the research was to determine the influence of the basic tillage systems on the change in soil fertility, yield and quality of corn grain in the soil and climatic conditions of the central zone of the Krasnodar Territory. The surveys were conducted in 2018–2020 on the experimental fields of the FSBSO “National Center of Grain named after P. P. Lukyanenko”. Soil – chernozems leached. All the experiments were carried out according to the standard methodology. In a stationary experiment, observations were performed to study several tillage practices: conventional tillage (25 cm depth plowing), mulch tillage with soil decompaction (reduced tillage done with a chisel plow to a depth of 32 cm for row crops), mulch tillage (deep tillage is excluded, disking to a depth of 10 cm twice or thrice is used instead). Plowing to a 25 cm depth improves the bulk of the soil in the 0–30 cm layer. However, chiseling to a depth of 32 cm and disking to a depth of 10 cm twice or thrice caused soil compaction. Standard tillage practice led to a decrease in the number of agronomically valuable aggregates (61.1 %) and their water resistance (59.4 %) compared to soil decompaction and minimum-tillage systems. The highest rates of productive moisture reserves were on the plots with traditional tillage and decompaction (140.6 and 141.5 mm, respectively, which is 14.7 % higher compared to the minimum mulching). The studied soil cultivation systems did not affect “1000-grain weight” but significantly affected the yield of grain from one ear (124.3 g) and the number of formed ears per one plant (1.04 pcs.). The corn yield on the fields with traditional and decompaction tillage methods was 56.9 and 55.9 c/ha, respectively; on minimum-tillage system, it decreased by 4.8 %. Protein content in grain harvested from the plots with traditional tillage practice was 11.4 %, which is higher compared to the minimum-tillage system. No significant differences were detected for crude ash and dry matter.

Organic Amendment vs. Mineral Fertilization under Minimum Tillage: Changes in Soil Nutrients, Soil Organic Matter, Biological Properties and Yield after 10 Years

Conservation tillage is recognized as a sustainable management practice, however its combination with organic residues application still constitutes a challenge in some areas. A field trial was established in a semiarid agro-ecosystem to study the effects of different crop nutrient sources under minimum tillage (MT). Application of organic amendments at the beginning of a five-year crop rotation (ORG treatment) was evaluated and compared to the control plot where wheat was continuously grown with traditional mineral fertilization (MIN treatment). In addition to wheat yield and biomass, several soil properties were measured (pH, soil nutrients (i.e., Olsen P, exchangeable K, and mineral N), soil organic matter (i.e., C, N, C/N ratio), potentially mineralizable nitrogen, total microbial activity and heavy metals) throughout the 10-year study. The wheat yield was significantly higher under the ORG treatment than under the MIN, although climatic conditions (e.g., rainfall) exerted a great influence too. The organic amendments increased soil nutrients content mainly right after their application but the levels were adequate for the whole crop rotation. Plots under organic amendment application did not accumulate significantly more soil organic matter than those mineral-fertilized, probably due to the low protective capacity of coarse-textured soils. The application of organic amendments under MT resulted in a promising management agro-ecosystem compared to the mineral fertilized because crop nutrients came from organic wastes, no herbicides were applied while the yields were higher.