IPNI SEAP Staff Publication List



Chuan, L., P. He, M.F. Pampolino, A.M. Johnston, J. Jin, X. Xu, S. Zhao, S. Qiu, W. Zhou. 2013.
Establishing a scientific basis for fertilizer recommendations for wheat in China.
Better Crops 97:10-13.

Chuan, L., H. Ping, M.F. Pampolino, A.M. Johnston, J.-Y. Jin, X. Xu, S. Zhao, S. Qiu and W. Zhou. 2013.
Establishing a scientific basis for fertilizer recommendations for wheat in China: Yield response and agronomic efficiency.
Field Crops Research, Vol 14, page 1-8.
Abstract: The inappropriate application of fertilizer has become a common phenomenon in wheat production systems in China and has led to nutrient imbalances, inefficient use and large losses to the environment. However, defining an appropriate fertilization rate remains the foundation to science-based nutrient management. This paper described a new fertilizer recommendation method for wheat in China based on yield response and agronomic efficiency using datasets from 2000 to 2011. The results showed that the mean yield responses of wheat to N, P and K were 1.7, 1.0 and 0.8 t/ha, respectively. Nitrogen was the nutrient most limiting yield, followed by P and then K. The soil indigenous nutrient supplies were 122.6 kg N/ha, 38.0 kg P/ha, and 120.2 kg K/ha. The mean agronomic efficiencies were 9.4, 10.2 and 6.5 kg/kg for N, P and K, respectively. There was a significant negative exponential relationship between yield response and indigenous nutrient supply, and a significant negative linear correlation between yield response and relative yield. It was also demonstrated a quadratic equation between yield response (x) and agronomic efficiency (y) (P < 0.05). The relationship between yield response (x) and agronomic efficiency (y) for N was yN = 0.3729xN 2 + 6.1333xN + 0.1438 (R2 = 0.76, n = 601), for P was yP = 0.5013xP 2 + 8.3209xP + 2.3907 (R2 = 0.65, n = 288), and for K was yK = 1.6581xK 2 + 9.099xK + 0.7668 (R2 = 0.58, n = 379). These equations were all incorporated as part of the Nutrient Expert for Wheat fertilizer recommendation decision support system. The results of multiple field experiments helped to validate the feasibility of the recommendation model and concluded that Nutrient Expert for Wheat could be used as an alternative method to make fertilizer recommendations in China.

Cook, S., J. Cock, T. Oberthür and M. Fisher. 2013.
On-farm experimentation.
Better Crops with Plant Food, Vol 97, Issue 4, page 17-20.
Abstract: The authors examine how farmer experimentation differs from 'conventional' experimentation, and how it might be reintegrated with conventional science and help in improving soil management. The focus is on the competence of farmers in using on-farm experimentation built around their experiences and an approach of "operational research", based on the observation and analysis of farm operations so as to improve them, to manage crops better.

Donough, C.R., J. Cock, T. Oberthür, K. Indrasuara, Rahmadsyah, A.R. Gatot and T. Dolong. 2013.
Estimating oil content of commercially harvested oil palm fresh fruit bunches - A step towards increasing palm oil yields.
Poster presented at the Malaysian International Palm Oil Congress (PIPOC), Malaysian Palm Oil Board (MPOB), Kuala Lumpur, Malaysia, 19-21 November 2013. Conference Proceedings, page 77.
Abstract: Oil palm growers are able to assign fresh fruit bunch (FFB) yields to individual blocks, and thus are able to manage their plantation (or smallholding) to optimize FFB yield. However, currently it is not possible to attribute oil extraction rate (OER), hence oil yield, in a similar way, because mills process FFB from many sources, deriving a common OER for all the FFB that is processed rather than for individual sources. OER depends on the intrinsic qualities of the FFB being milled, which is likely to differ from one batch of FFB to another, hence assessment of milling performance is better based on extraction efficiency rather than OER per se. The Southeast Asia Program of the International Plant Nutrition Institute (IPNI SEA) recently showed that practices aimed at maximizing FFB yield may not necessarily maximize OER. The bunch analysis (BA) method adapted by IPNI SEA for assessing oil content of FFB from commercial-scale harvesting in Indonesia can be implemented by plantations without much difficulty. BA and harvest audit data together allows growers to compute their Field Oil Recovery Efficiency (FORE), an assessment of the effectiveness of field practices on crop recovery and oil content. Pre-milling estimates of oil content (EOC) in harvested FFB allows mills to better measure their process performance based on their Mill Oil Recovery Efficiency (MORE). Knowledge of EOC will allow mills to pay growers for the oil content of their crop, providing further motivation to growers to improve FORE. These recovery efficiency measures allow a more holistic analysis of the overall oil recovery process involving the growers and the mills, likely leading to reduced friction and better overall performance.

Gerendas, J., B. Utomo, K. Martoyo, C.R. Donough and T. Oberthür. 2013.
Effect of nutrient application frequency on nutrient uptake in oil palm production on sandy soils.
Proceedings of the Malaysian International Palm Oil Congress (PIPOC), Malaysian Palm Oil Board (MPOB), Kuala Lumpur, Malaysia, 19-21 November 2013. Page 95.
Abstract: Oil palm cultivation has expanded rapidly in Kalimantan, Indonesia, in recent years. Sandy soils are common in the region, in some areas coupled with inadequate and unevenly distributed rainfall. On such sandy soils, loss of nutrients by leaching can be high during times of high rainfall. Higher frequency of applications on such soils can be expected to increase the efficiency of applied fertilizers i.e. fertilizer recovery efficiency (FRE). In a project started in October 2011, blending of individual fertilizers prior to field application allowed for four rounds each of N, P, K, Mg, S, and B per year in the improved practice treatment (here referred to as nutrition best management practice, BMP), compared to the control treatment where the same fertilizers were applied individually according to standard estate practice (SEP). FRE was based on the ratio between (a) nutrients removed (in FFB) plus nutrients immobilized (in palm trunks), and (b) nutrients supplied from applied fertilizers.
After one year, the SEP treatment recorded a FRE of 53% for N, 71% for P, 37% for K and 62% for Mg. Applying each of these nutrients four times a year increased their efficiency by 10% and 18% for N and K, respectively, while the efficiencies of P and Mg were not affected. P and Mg recovery efficiencies were likely moderated by use of rock phosphate (RP) and dolomite (DOL), respectively, in the plantation prior to the project.
While the project continues for several more years, the encouraging first year results gives credence to the hypothesis that higher nutrient application frequency will improve FRE for oil palm grown in the type of conditions prevailing at the project site. This is especially important for the profitability of plantations and for sustainable intensification of oil palm production in similar conditions elsewhere.

IPNI. 2013.
Planters' Diary 2013.
International Plant Nutrition Institute, Penang, Malaysia.

IPNI. 2013.
Poster - Nutrient deficiency symptoms in oil palm. (in Burmese).
International Plant Nutrition Institute, Penang, Malaysia.

IPNI. 2013.
Poster - Symptômes des deficiencies minérales chez le palmier à huile (in French).
International Plant Nutrition Institute, Penang, Malaysia.

Oberthür, T., C.R. Donough, J. Cock, Rahmadsyah, G. Abdurrohim, K. Indrasuara, A. Lubis and T. Dolong. 2013.
Opportunities for research and development in oil palm fertilization to support sustainable intensification.
Better Crops with Plant Food, Vol 97, Issue 2, page 17-20.
Abstract: The Southeast Asia Program of IPNI (IPNI SEAP) has developed a process to reduce yield gaps in oil palm plantations using Best Management Practices (BMPs). This process appraises the yield that can be obtained with BMPs on a set of commercial production blocks, evaluates the benefits from packages of management improvements, and also assesses the most appropriate BMP for a particular site. Estates can then identify BMPs suitable for yield intensification that work on a small set of commercial plots and use this information to make investment decisions for larger areas with a higher level of confidence.

Satyanarayana, T., K. Majumdar, M. Pampolino, A.M. Johnston, M.L. Jat, P. Kuchanur, D. Sreelatha, J.C. Sekhar, Y. Kumar, R. Maheswaran, R. Karthikeyan, A. Velayutahm, G.A. Dheebakaran, S. Vallalkannan, T. Sherene, T.H. Ranjith, D. Shivamurthy, Y.R. Aladakatti, D. Chiplonkar, R. Gupta, D.P. Biradar, S. Jeyaraman and S.G. Patil. 2013.
Nutrient Expert®: a tool to optimise nutrient use and improve productivity of maize.
Better Crops 97:21-24.
Abstract: Nutrient Expert® (NE)-based field-specific fertilizer recommendations offered solutions to the farmers of southern India for better nutrient use in maize under the current scenario of escalating fertilizer prices. Results from validation trials, comparing NE-based recommendations with farmer practice and the state recommendation in 82 farmer fields of southern India, demonstrated the utility of the decision support system tool in improving the yield and profitability of maize farmers in the region.

Xu X., P. He, M.F. Pampolino, L. Chuan, A.M. Johnston, S. Qiu, S. Zhao and W. Zhou. 2013.
Nutrient requirements for maize in China based on QUEFTS analysis.
Field Crops Research, Vol 150, page 115-125.
Abstract: Estimating balanced nutrient requirements for maize (Zea mays L.) in China is essential to manage nutrient application more effectively for increasing crop yield and reducing the risk of negative environmental impact. On-farm datasets were collected from 2001 to 2010 from China's maize-producing regions to investigate the relationship between grain yield and nutrient accumulation in the above-ground plant dry matter of commercial hybrid maize. The QUEFTS (quantitative evaluation of the fertility of tropical soils) model was used to estimate the balanced nitrogen (N), phosphorus (P) and potassium (K) requirements in China's maize growing regions. The analysis indicated that there were great differences in the grain yield and nutrient uptake between spring maize and summer maize: minimum and maximum internal nutrient efficiencies (IE, kg grain per kg nutrient in the above-ground plant dry matter) were 36 and 89 kg grain per kg N, 135 and 558 kg grain per kg P, 30 and 132 kg grain per kg K for spring maize, 31 and 70 kg grain per kg N, 108 and 435 kg grain per kg P, 32 and 110 kg grain per kg K for summer maize. The model predicted a linear increase in grain yield if nutrients were taken up in balance until yield reached about 60-70% of the potential yield. To produce 1000 kg of spring maize grain yield, 16.9 kg N, 3.5 kg P and 15.3 kg K were required by above-ground dry matter of maize, and the corresponding IE were 59 kg grain per kg N, 287 kg grain per kg P and 65 kg grain per kg K. For summer maize, 20.3 kg N, 4.4 kg P, 15.9 kg K were needed to produce 1000 kg maize grain in the linear part, and the corresponding IE were 49 kg grain per kg N, 227 kg grain per kg P and 63 kg grain per kg K. Optimal N:P:K ratios in plant biomass were 4.83:1:4.37 for spring maize and 4.61:1:3.61 for summer maize, respectively. QUEFTS analysis also indicated that a balanced N, P and K removal by grain to produce 1000 kg grain, when the target yield reached about 80% of the potential yield, the grain absorption of N, P and K accounted for 54%, 69% and 23% of above-ground N, P and K uptake for spring maize, and 67%, 85% and 23% for summer maize, respectively. Two-year field validation experiments indicated that the QUEFTS model could be used for estimating balanced nutrient requirements and contributed to developing fertilizer recommendations.

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