Long-Term Effects of Different Passages of Vehicular Traffic on Soil Properties and Carbon Storage of a Crosby Silt Loam in USA

The passage of vehicles with heavy axle loads causes soil compaction, and this adversely affects soil properties and crop yield.The adverse effects can persist for several years due to significant changes in key soil properties. However, the mechanisms of the aforementioned effects are not well understood for conservation agriculture(CA)(e.g., no-till(NT)) wherein the use of heavy machinery is considerably common. Therefore, known compaction forces(0 Mg load for compaction(NT-0, control), two passages of 2.5 Mg water wagon axle load(NT-2), and four passages of 2.5 Mg water wagon axle load(NT-4)) were applied to all the plots annually for 20 consecutive years. The experiment was established in 1997 at the Waterman Agricultural and Natural Resources Laboratory(WANRL), Ohio State University, Columbus, Ohio. Each treatment was replicated thrice. Soil samples were obtained in November2016 to determine the effects of variations in the axle load and vehicular passages on carbon(C) and nitrogen(N) storage and selected soil properties of a Crosby silt loam soil under NT-based corn-soybean rotation with residue retention in Central Ohio, USA. Three locations were also randomly selected in an adjoining natural woodlot(WL) soil plot and sampled(30 m away from the compaction field) to compare the effects of vehicular traffic on soil under NT with WL soil. Results revealed that soil bulk density(ρb) and total porosity at 0–10 and 10–20 cm depths were not affected by the passages of vehicular traffic for 20 years under the NT system.The penetration resistance(PR)(1.86 and 2.03 MPa at 0–10 and 10–20 cm soil depths, respectively) was significantly higher under NT-4 compared with that under other treatments. Saturated hydraulic conductivity at 0–10 and 10–20 cm soil depths ranged from19.7 to 31.4 and 18.5 to 29.5 mm d^(-1), respectively, across all the treatments. The proportion of macroaggregates(> 0.25 mm) and microaggregates(< 0.25 mm), mean weight diameter and geometric mean diameter of aggregates, pH, electrical conductivity, and C and N contents and storage did not differ significantly between the treatments at either of the sampling soil depths. The data indicated that 2 to 4 passages of vehicles with 2.5 Mg of axle load did not cause significant compaction of the Crosby silt loam under NT compared with that under natural WL. Therefore, the continuous cultivation of row crops with NT and residue retention is feasible with passages of vehicular traffic for well-drained soils in Central Ohio.

Crop productivity,soil health,and energy dynamics of Indian Himalayan intensified organic maize-based systems

The sustainability of prevailing maize-fallow system in rainfed ecosystems of the Eastern Himalayan region(EHR)of India is often questioned due to poor economic return and negative impact on soil health.Hence,the six cropping systems,maize-fallow(M-F),maize t cowpea-rapeseed(M t C-Rs),maize t cowpea-buckwheat(M t C-Bw),maize t cowpea-barley(M t CeB),maize t cowpea-garden pea(M t C-GP)and maize t cowpeaerajmash(M t C-R)in the main plot and three soil moisture conservation measures,no-mulch(NM),maize stover mulch(MSM)and maize stover t weed biomass mulch(MSM t WBM)in sub-plot were evaluated for four consecutive years(2014-18)at a Research Farm in fixed plot fashion.Results indicated that cowpea co-culture with maize and inclusion of winter crop increased maize yield by 6.2e23.5%over M-F.Among the systems,the M t C-GP recorded the highest crop productivity.The residual effect of MSM t WBM increased maize grain yield by 19.1%over NM.Cultivation of maize t cowpea-winter crops significantly improved the available N(3.2e12.9%),P(3.6 e12.7%),K(1.9e26.3%),organic carbon(9.2e16.8%),microbial biomass carbon-MBC(15.2e43.9%)and dehydrogenases-DHA(17.2e42.3%)in soil at 0e15 cm depth as compared to M-F.The M t C-GP also recorded maximum net return(US$2460 ha1),benefit:cost(B:C)ratio(2.86)and energy use efficiency(7.9%).The MSM t WBM recorded higher net return(US$1680 ha1)and B:C ratio(2.46)over NM.Hence,cowpea t maize-garden pea(M t C-GP)along with the application of MSM t WBM is a sustainable production practice to intensify the organically managed maize-fallow system in rainfed regions of the EHR of India and other similar ecosystems.

Potential of conservation tillage and altered land configuration to improve soil properties,carbon sequestration and productivity of maize based cropping system in eastern Himalayas,India

Poor soil properties especially low soil organic carbon(SOC)and nutrient and water retention capacities are major concern for sustainable agriculture in Himalayas.Field experiments were conducted to assess the effects of six combinations of tillage[conventional tillage(CT)and no-till(NT)]and land configurations[flat bed planting(FB),ridge and furrow planting(RF),and raised bed planting(RB)]on productivity and carbon(C)-sequestration potential of maize[(Zea mays L.)for green-cob in summer]-maize(for grains in rainy season)-field pea[(Pisum sativum L.in winter]cropping system under humid mildtropical climate of Tripura,India.The maize under NT-FB in 2012 and NT-RF in 2013 produced significantly higher green cob yield than that under CT-RF.However,in rainy season,CT produced higher maize grain yield than NT systems.Field pea seed yield was significantly the highest under NT-RB.After two cropping cycles,NT systems had higher available N,P,K and 18.6e31.4%higher soil moisture content after rainy season maize than CT system.The highest SOC-stock(0e30 cm)was observed under NT-FB,whereas,SOC-sequestration rate was maximum under NT-RB(0.85 Mg ha1 year1).Therefore,NT based systems can enhance the productivity and improve SOC-sequestration in cultivated soils of eastern Himalayas.Hence,study recommended adoption of NT-RB/NT-FB to raise maize-maize-field pea system for improving productivity,improving C-sequestration and soil properties in the eastern Himalayas and similar eco-regions elsewhere.

Double mulching improves soil properties and productivity of maize-based cropping system in eastern Indian Himalayas

A field experiment was conducted for two consecutive years at North Eastern Indian Himalayan region to assess the effect of soil moisture conservation measures on soil and water productivity of different rainfed maize(Zea mays L.)-based cropping sequences.Results revealed that double mulching with in-situ maize stover mulch(MSM)+fresh biomass of white hoary pea(WHP-Tephrosia candida)and MSM+fresh biomass of ragweed(RW-Ambrosia artemisiifolia)improved soil moisture content(SMC)and leaf relative water content of crops during dry season.The soil organic carbon(SOC)content and stocks under MSM+WHP and MSM+RW mulches were significantly higher than that under no mulch at 0-15 cm depth.The soil microbial biomass carbon and dehydrogenase activity were maximum under MSM+WHP/RW.The highest system productivity was obtained from maize-French bean(Pole type-PT)sequence under MSM+RW followed by MSM+WHP.The water productivity was the highest under MSM+WHP.While SOC content was the highest under maize-French bean(PT),the maximum plant available nitrogen and phosphorus were obtained under maize-black gram sequence.Thus,double mulching technology involving MSM and RW(available in plenty)is a viable option for improving soil,crop and water productivity under rainfed hill ecosystems of eastern Indian Himalayas.

Application of remote sensing for sustainable agriculture and forest management

Global warming resulting from greenhouse effect has threatened to the sustainability of agriculture,forest and land surface globally.A significant rise in extreme weather events has been observed worldwide,particularly in developing countries[1].In the changing climatic era,the economic importance of the remote sensing and geographical information system(GIS)to monitoring forests and agricultural resources is imperative to the development of agro-ecosystem services and the products responding to user needs[2].The applications of the remote sensing for forestry and agriculture,including the estimation of the land surface,biophysical variables,forest vegetation’s,methods for mapping land cover,primary soil properties,the estimation of the forest cover area,and the contribution of remote sensing for crop and water monitoring to manage adverse conditions.