Global CA-CoP CONSERVATION AGRICULTURE COMMUNITY OF PRACTICE

for sustainable agriculture, land use and ecosystem management


Dear Subscribers,

Please see herebelow the June 2021 Cornell Conservation Agriculture Newsletter.

Thank you Professor Hobbs 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: Mon, 31 May 2021 at 19:07
Subject: June 2021 Cornell CA newsletter
To: Amir Kassam <[log in to unmask]>


Dear Amir: Here is our June 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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Farmers adopting CA in Southern Africa have rarely fully implemented all its components, resulting in different combinations of no-tillage, crop rotation, and permanent soil cover being practiced, thus resulting in variable yield responses depending on climatic and soil conditions. This study used 8 locations in Southern Africa to evaluate how partial and full implementation of these components affected crop yield and yield stability compared with conventional tillage alone or combined with mulching and/or crop rotation. Across different environments, the addition of crop rotation and mulch to no-tillage increased maize grain by 6%, and the same practices added to conventional tillage led to 13% yield increase. Additive main effects and multiplicative interaction analysis allowed clarifying that mulch added to no-tillage gives stable yields on sandy soil with high rainfall. Similarly, mulch added to conventional tillage gives stable yield on sandy soil, but under low rainfall. The paper highlighted the crucial role of mulch to enhance the stability and resilience of cropping systems in southern Africa.
This paper studied the effects of tillage, crop residues, and green manure on soil carbon pools and hydrolytic enzyme activity in a sandy loam after five cycles of the rice-wheat system (RWS). Four main plot rice treatments included (1) puddled transplanted rice (PTR) with no wheat straw, (2) PTR with 25% wheat stubbles (12–15 cm long) retained, (3) PTR with no wheat straw plus GM, and (4) PTR with 25% wheat stubbles plus GM. Three subplots treatments in wheat were (1) conventional tillage with rice straw removed, (2) zero tillage (ZT) with rice straw removed, and (3) ZT with 100% rice straw retained as a surface mulch. The results showed that PTR with wheat stubbles retained plus GM and ZT wheat with rice straw retained (ZTWRS100) significantly increased all the carbon pools and hydrolytic enzymes except phenol oxidase and peroxidase activities.
This study was chosen because it had peanuts growing under CA. This study evaluated the effects of different CA practices on soil moisture, soil fertility, yield, and profitability of peanut systems. Treatments consisted of four tillage practices (conventional tillage [CT], minimum tillage [MT], zero tillage [ZT], and rotary tillage [RT]); two residue management practices (residue removal [NR] and residue retention [RR]), and two intercropping systems peanut+pigeonpea [PP] and peanut+cotton [PC]. Minimum tillage and residue management practice RR improved soil moisture content, soil porosity, soil organic C, nutrient status (mainly at 0–15 cm), and soil enzymatic activities and decreased soil temperature variation and soil penetration resistance. Among the cropping systems, PP was found more productive and profitable as compared to PC. 
This paper looks at various methods for scaling new agricultural uses .practices and technologies and assess their effectiveness. They collected data from 875 smallholder farmers. in central Mozambique. They used a continuous treatment model within the framework of a generalized propensity score matching to empirically assess the effectiveness of community-based extension activities in fostering the adoption of a set of conservation tillage practices . The results show that controlling for socio-demographic factors such as gender of decision maker, land size and access to government services, the area under conservation tillage doubled when respondents had been exposed to targeted extension activities for at least six seasons, from a baseline exposure of two seasons. The study offers an important first step in making an empirical case for multi-year investments in extension activities.
This paper from Bangladesh looks at blade design and rotational speed for a two wheel tractor (2WT) to establish maize by strip-tillage. PTO's, power operated tillers, that can be attached 2WTs are becoming popular in this country. They conducted experiments for 2 years on loam and clay soils. Four blades designed with varying tip angles and five levels of rotational speed were compared with commercially available C-shaped blades sold with 2WTs. Torque and power requirements for strip tillage decreased with decreasing blade tip angle and rotational speed. The best combination of blade design and rotational speed was found with a 15° blade tip angle at 320 RPM on both soil types. Machinery operators will require educational efforts to learn how to fine-tune RPM to improve crop establishment and achieve more sustainable crop establishment systems.
This study looked at various treatments that affect P availability and P-solubilizing microbes (PSMs) in a 15 year long term, CA agronomic trial in Western Kenya. They selected 8 treatments for comparisons. Reduced tillage significantly (P < 0.05) increased microbial biomass phosphorus (MBP) and abundance of different PSMs relative to conventional tillage, though the results were not consistent for some species. Residue addition significantly increased maize grain yield, MBP and abundance of different PSMs compared to systems without residue addition. Some PSM strains were significantly more abundant in maize and soybean intercropping systems compared to rotation, and vice versa. They conclude that not only the agronomic inputs applied but also tillage and cropping systems employed can variably affect the soil microbial populations.
Soils under NT in Brazil have been chiseled to correct compaction. This paper hypothesizes that use of crops with deep roots in the rotation could be an alternative to mechanical chiseling. The objective in this study was to evaluate changes in SOC stocks, root development, and crop yield over time caused by mechanical and biological chiseling in a long-term no-till system (18 years). The treatments were 1) No-till cover crop (NT-CC). 2) No-till Mechanical Chiseling (NT-MC) and 3) No-till Biological Chiseling (NT-BC). Compared to NT-CC, the use of NT-MC depleted the SOC stocks by -0.41 Mg ha−1 year−1 and raises concerns about this practice. NT-MC also depleted proxies for microbial- related C pools such as hot-water and permanganate extractable C. However, the results demonstrated that the use of radish as an intercrop for alleviating soil compaction was a good alternative to replace mechanical chiseling in compacted NT fields due to its superior performance in increasing SOC stocks, promoting higher root development, and crop yield.






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