Global CA-CoP CONSERVATION AGRICULTURE COMMUNITY OF PRACTICE

for sustainable agriculture, land use and ecosystem management


Dear Subscribers,

Please see herebelow the July Cornel CA Newsletter for your kind attention.

Thank you Peter for sharing.

Amir Kassam

Moderator

Global CA-CoP

e-mail: [log in to unmask]

URL: http://www.fao.org/conservation-agriculture


---------- Forwarded message ---------
From: Peter Hobbs <[log in to unmask]>
Date: Thu, 1 Jul 2021 at 14:44
Subject: July Cornell CA Scoopit newsletter
To: Amir Kassam <[log in to unmask]>

Dear Amir: Here is our July 2021 Conservation Agriculture Scoopit Research Update. You can also view online at https://www.scoop.it/topic/conservation-agriculture-by-conservation-ag?curate=true&null 
Can you send this out to people who get your listserv material? The hard copy is below.

An easier link to see all the research papers on CA is as follows:

Also, visit our main website at http://soilhealth.org for news and other CA information. Please use this link since we had to move our web site to a new server and this links takes you to the CA web site.

Many thanks for helping to distribute this. Peter

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This paper looks at new assessment approaches that are needed to quantify how conservation agriculture might contribute to soil health improvement and soil organic C (SOC) sequestration. SOC sequestration was calculated as the summation of SOC stock greater than the baseline condition at 30-cm depth. Data from literature sources were mathematically fitted with this new approach as a validation. Two on-farm surveys with different agricultural management practices (5–40 yr) in the southeastern United States yielded preliminary estimates of SOC sequestration. The interquartile range of calculated SOC sequestration was 4.2–9.4 Mg C ha–1 for conventional-tillage cropland (n = 45 fields), 13.6–29.7 Mg C ha–1 for no-tillage cropland (n = 97 fields), and 15.9–26.1 Mg C ha–1 for perennial pasture (n = 29 fields).
Based on the findings from peer-reviewed literature, this review aims to identify unsustainability issues and research gaps in the R–W system in South Asia and propose possible solutions to mitigate those issues and technological interventions to close the research gaps. Issues that the review has identified are declining crop, water and land productivity, deterioration of soil health, emissions of greenhouse gases due to intensive tillage and residue burning, deepening of groundwater levels and shift in weed flora and development of herbicidal resistance in crops. Potential solutions or technological interventions to mitigate the unsustainability issues include resource conservation technologies (RCTs) such as rice residue management, reduced tillage, laser land leveling, soil matric potential based irrigation scheduling, delayed rice transplanting, cultivation on permanent raised beds, direct-seeded rice (DSR), mechanical transplanting of rice and crop diversification with legumes. Sustainable R–W production technologies with reduced water, energy and C footprints are required for increased water and energy productivity and C sequestration for the NW IGPs of South Asia.
This a paper that looks at selection of suitable wheat genotypes for CA that maintain productivity under drought conditions. The screened bread and durum varieties under CT and CA for three crop seasons under rainfed conditions in Iran. The wheat cultivars performed better in conventional than conservation agriculture system with grain yield superiority varied from 4 to 35%, depending on amount and distribution pattern of precipitation over crop seasons. They concluded there was a positive interaction of genotype and traits under the two tillage systems with some traits (i.e., number of spike/m−2, SPAD reading, normalized difference vegetative index (NDVI), days to heading, 1000-kernel weight and grain filling duration)  effective in genotype adaptation to a particular system. The wheat genotypes significantly interacted with different tillage systems, implying the need for specific adaptation to tillage systems and environments.
This field study evaluated the effects on cropping sequences and tillage systems on SOC and N fractions. No-till (NT) and rotary tillage (RT) were combined with four cropping sequences: wheat-soybean-wheat-maize (WSWM), wheat-maize-wheat-soybean (WMWS), wheat-soybean-wheat-soybean (WS) and wheat-maize-wheat-maize (WM). Tillage systems affected SOC and N in topsoil rather than deeper, but cropping sequences in the whole sampling depth (0-50cm). NT had significantly higher SOC concentrations than RT at the 0–10- (17% higher) and 20–30-cm (19% higher) soil layers. NT had 17% significantly higher N contents than RT at the 0–10-cm soil layer, but RT had 21% significantly higher N accumulation at the 10–20-cm soil layer. The particulate organic carbon (POC) was highest in WM and lowest in WS cropping sequence at 0–10-cm soil depth. Particulate organic nitrogen (PON) was significantly higher in soybean-included cropping sequences only at 0–10-cm soil depth. Overall, their findings suggested that NT especially with soybean could be a suitable practice to sequester SOC and N in the North China Plain.
This study looks at the data from a long-term trial in Eastern India with 4 treatments: Traditional rice-wheat (TA), Full CA (fCA), and two partial CA's, pCA1 and pCA2 that differ in crop establishment methods, cropping system and crop residue management. Soil health parameters were measured in the 11th year of the experiment. The results revealed a beneficial effect of CA and 46 and 40% increase in SOC concentration and stock, respectively, under fCA over TA in the 0–7.5-cm soil layer. The effect of partial CA (pCA1 and pCA2) was variable, but an increasing trend was always observed under pCA compared to TA. The yield of rice in CA was comparable to or higher than in TA, whereas the system rice equivalent yield was always higher (38–53%) under CA than under the conventional practices. They conclude that CA can be promoted for sustainability of a rice–wheat system due to higher productivity (38–53%).
Burning of rice residues in the rice-wheat system especially in NW India is causing severe air pollution. Since the use of new locally produced seed drills that can plant into loose straw provides one solution to this problem, this paper was included. The objectives of this paper are to estimate the crop residue burning and emissions from crop residue burning, to recommend interventions in crop residue management and to propose a crop residue management-bioeconomy model incorporating strategies to sustainably manage the crop residues through interventions that enable waste valorization, food and nutritional security, farmers’ livelihood and sustainable agricultural production system. This paper provides some alternative ways to eliminate residue burning. that can provide lessons for other regions with similar problems.
This paper applied two independent soil health assessment approaches to evaluate the impacts of 40-yr conservation tillage (CST) and additional 4-yr cover cropping on a range of soil health indicators and the overall soil health in typical southeastern Coastal Plain soils of the USA. The Soil Management Assessment Framework (SMAF) and Cornell's Comprehensive Assessment of Soil Health (CASH) were used to calculate soil health indices. When compared to conventional tillage, 40-yr CST increased active carbon (C) from 301 to 420 mg kg–1 and organic nitrogen (N) mineralization potentials from 0.78 to 0.91 mg kg–1 d–1, but it reduced soil electrical conductivity from 133 to 101 μs cm–1. No difference in soil aggregate stability, total C, extractable phosphorous and potassium, microbial biomass C, respiration, and glucosidase activities were observed between the two tillage treatments. Increasing organic inputs along with CST is seemingly the optimal management option.
This study looked at three climate smart technologies (CSA) experimented by farmers in Malawi in terms of soil quality and maize yields and compared to CFS. The three technologies were conservation agriculture (CA), maize–pigeonpea (Maize-PP) intercrops and a local organic and inorganic soil amendment known as Mbeya fertilization (Mbeya-fert), from 2018 to 2019. Particulate organic matter, soil organic carbon (SOC), N, P, K, Ca and Mg all significantly improved while bulk densities were lowered under the three CSA systems compared to conventional farmer systems (CFS). CA and Mbeya-fert improved maize yields by 51 and 19%, respectively, compared to conventional farmer practices. They concluded that employing these CSA technologies could enable farmers to be more resilient, productive and adapt better to climate change shocks leading to improved food security and livelihoods.
This paper provides information to society and decision-makers about the effectiveness of of conservation agriculture (CA) principles with zero tillage (ZT/CA) and integrated crop–livestock–forest (iCLF-CA) systems as central policies to mitigate soil erosion, the main agent of land degradation and productivity loss in Brazil. The annual potential for soil erosion with intensive conventional tillage and monocropping, considering land use and cover in 2017, is 3.0 billion tons. The economic impact, based only on replacement of nutrient losses, is estimated to be 15.7 billion US$ yr−1. The annual economic impact of the adoption of CA principles by controlling soil erosion was estimated at 1.5 billion US$ for ZT/CA in 2017 and 0.5 billion US$ for iCLF-CA in 2015. They conclude that the positive impacts of the adoption of CA principles in Brazil are the result of the determination of farmers, among many actors, and of the effectiveness of government plans and policies.





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