The main physical properties of planosol in maize(Zea mays L.) cultivation under different long-term reduced tillage practices in the Baltic region

The impact of sustainable reduced tillage （RT） on the physical properties of soil is well documented worldwide; however, there is no precise information about the influence of long-term RT or no-till （NT） on the soils at the boundary for grain maize-growing in the semi-humid subarctic climate conditions of the Baltic states, especially on the formation of a hard- ened upper soil layer （10-15 cm in depth） --＂loosening hardpan＂. This study was carried out at the Research Station of Aleksandras Stulginskis University, Lithuania from 2009-2012. The investigations were based on a long-term （since 1988） field experiment. The aim of the investigation was to ascertain the influence of reduced primary tillage on the main soil＇s physical properties. This study examined soils that were deep ploughing （DP）, shallow ploughing （SP）, deep cultivation （DC）, shallow cultivation （SC）, and no-till （NT）. Reducing the tillage intensity to NT had no significant effect on the structural soil＇s composition; however, the stability of the structure of the 〉1 and 〉0.25 mm-size fractions was significantly higher in the non-reversibly tilled （DC, SC） and NT plots. The penetration resistance of the DP soils was less after primary tillage and wintering, and became similar to the NT plots at the end of the maize growth season. After primary tillage and wintering, the soil moisture content in the upper soil layer （0-5 cm depth） of the NT plots was 17-49 and 16-18% higher than that in the DP. Long-term reduction of primary tillage up to NT generally had no significant effect on the moisture content and soil bulk density of the 0-10 and 10-20 cm layers. The results showed that long-term RT stabilized the physical quality of soil. Less soil penetration resistance was established in the DP plots compared to both RT and NT, however, indicators of the formation of a uniform ＂loosening hardpan＂ layer were not found. It is summarized that long-term RT or NT systems stabilize, or may increase, the physical quality of soil in crop cultivation with low inter-row coverage potential （maize）, and could be applied in semi-humid subarctic climate conditions as a good option to prevent soil degradation.

Improved crop protection and biodiversity of the agroecosystem by reduced tillage in rice paddy ffelds in southern China

Agricultural sustainability has benefited from the broad adoption of conservation agriculture(CA)practices for decades,in which the reduction of mechanical disturbances to soil(also known as reduced tillage,RT)is one of the most essential principles for CA implementation.Many studies have recommended the advantages of CA practices in the promotion of biodiversity,but the integrated impacts on crop productivity and biodiversity remain unclear.Since CA has been applied in rice production in the subtropical area of southern China for several years,the effects of CA,particularly the RT methods,need to be evaluated for the local and long-term adoption.In this study,we established an integrated network to illustrate how the reduction of tillage intensity influenced organisms including invertebrates(such as rice pests and their predators),pathogens and weeds,and then led to an impact on rice yield.The two-year study demonstrated that major rice pests,such as rice planthoppers,stem borers and apple snails,were effectively controlled by RT practice.Similarly,the occurrence of common diseases declined with less tillage.Compared to the conventional tillage(CT)treatment,the density of weeds in paddy fields deceased significantly in the RT treatment.In addition,the diversity and richness of pest predators increased remarkably in paddy fields where either reduced or no tillage was applied,which highlighted the significance of a CA strategy for the promotion of biodiversity in the agroecosystem.More importantly,the rice yield gradually increased after the two-year reduction of tillage.Taken together,our results suggest that the reduction of tillage intensity is beneficial for the protection of rice crops from various pests,and facilitates the sustainability of the agroecosystem and rice yield,which provides a solid basis and novel insights for the establishment of sustainable agroecosystems by CA-related practices in rice production in southern China.

Genotype×tillage interaction and the performance of winter bread wheat genotypes in temperate and cold dryland conditions

Growing concerns for food security and the alleviation of hunger necessitate knowledge-based crop management technologies for sustainable crop production.In this study,13 winter bread wheat genotypes(old,relatively old,modern,and breeding lines)were evaluated under three different tillage systems,i.e.,conventional tillage(CT,full tillage with residue removed),reduced tillage(RT,chisel tillage with residue retained)and no-tillage(NT,no-tillage with residue retained on the soil surface)in farmer’s fields under rainfed conditions using strip-plot arrangements in a randomized complete block design with three replications in the west of Iran(Kamyaran and Hosseinabad locations)over two cropping seasons(2018–2019 and 2019–2020).The main objectives were to investigate the effects of tillage systems and growing conditions on the agronomic characteristics,grain yield and stability performance of rainfed winter bread wheat genotypes.Significant(P<0.01)genotype×tillage system interaction effects on grain yield and agronomic traits suggested that the genotypes responded differently to the different tillage systems.The number of grains per spike and plant height were positively(P<0.0)associated with grain yield under the NT system,so they may be considered as targeted traits for future wheat breeding.Using statistical models,the modern cultivars(“Sadra”and“Baran”)were identified as high yielding and showed yield stability across the different tillage systems.As per each tillage system,genotype“Sadra”followed by“Zargana-6//Dari 1-7 Sabalan”exhibited higher adaption to CT;while cultivars“Jam”and“Azar2”showed better performance under the RT system;and cultivars“Varan”and“Baran”tended to have better performance expression in the NT condition.The increased grain yields achieved in combination with lower costs and greater profits from conservation agriculture suggest that adapted cultivar and NT systems should be evaluated and promoted more widely to farmers in the west of Iran as an attractive package of crop management technologies.In conclusion,variations in the performance of genotypes and the significant genotype×tillage system interaction effects on grain yield and some agronomic traits assessed in this study suggest that the development and selection of cultivars adapted to the NT system should be considered and included in the strategies and objectives of winter wheat breeding programs for the temperate and cold dryland conditions of Iran.

Distribution of soil water-stable aggrega-tes and organic carbon content affected by tillage systems:a meta-analysis

A better understanding of soil carbon(C)distribution within aggregate fractions is essential to evaluating the potential of no-till for sustaining productivity and protecting the environment.A meta-analysis on 744 comparisons from 34 studies was conducted to determine the effects of three different tillage treatments(conventional mouldbould ploughing tillage(CT),reduced tillage(RT)and no tillage(NT))on water-stable aggregate size distribution,soil C concentration in aggregate fractions.The meta-analysis indicates that compared with CT treatment,NT/RT significantly(P<0.05)increases macro-aggregate above 20 cm by 20.9%-82.2%(>2.00 mm)and 5.9%-19.1%(0.25-2.00 mm),whereas NT/RT significantly reduces micro-aggregate and silt clay fractions above 20 cm.NT/RT significantly(P<0.05)increases the SOC in macro-aggregate(>0.25 mm)and micro-aggregate(<0.25 mm)size classes above 20 cm soil depth compared with CT.The results suggest that soil sampling depth should be considered to evaluate the influence of tillage systems on the distribution of soil aggregate,and the content of aggregate-associated C content.

Tillage and crop management impacts on soil loss and crop yields in northwestern Ethiopia

Lack of appropriate agronomic practices is one of the major causes for soil erosion and low yields in teff(Eragrostis tef[Zucc.])production in Ethiopia.A 3-yr study was conducted at the Aba Gerima watershed in northwestern Ethiopia,to investigate the effects of two tillage practices(reduced tillage[RT]and conventional tillage[CT]),two planting methods(row planting[RP]and broadcast planting[BP]),and two compaction options(with[+T]and without[-T]trampling)on soil loss and teff yields in a split-split plot arrangement.Sediment concentration ranged from 0.01 to 5.37 g L^(-1)(mean,0.25 g L^(-1))in our study.Accordingly,the estimated total(August-October)soil loss ranged from 0.2 to 0.5 t ha^(-1)(mean,0.3 t ha^(-1)).The sediment concentration and total soil loss were significantly influenced(P<0.05)by tillage,planting methods,and trampling only in the third monitoring year.RT reduced soil loss by 19% relative to that of CT,whereas RP resulted in a 13%reduction in soil loss over BP.The-T plots showed a 15%reduction in soil loss as compared to+T plots.Results revealed significant increase in soil total carbon and nitrogen in RT and-T.Less soil loss and greater teff grain yield were obtained in plots with improved agronomic practices(RT and RP)compared to conventional ones(CT and BP).Based on our findings we conclude that the use of RT,RP,and-T practices can effectively minimize soil loss without any crop yield penalty.

Conservation Agriculture in Europe

The adoption of Conservation Agriculture(CA)in Europe varies according to the ecological regions of the continent.Although Europe is behind other countries in adoption of CA,the indicators for future progress are encouraging.The area where CA is applied is growing rapidly because of increasing environmental awareness,including soil protection,and because of the need to reduce production costs.The European Conservation Agriculture Federation(ECAF)plays an important role in the adoption and dissemination of CA practices,and in discussions involving CA and the EU Common Agricultural Policy(CAP)reform.Yield performance and stability,operating costs,environmental policies and programs of the Common Agricultural Policy(CAP),and climate change will likely be the major driving forces defining the direction and for the extension of CA in Europe.The role of agriculture in climate change mitigation in the EU is discussed in the paper.