Nutrient Management Key Check 5 Sufficient nutrients from

Nutrient Management Key Check 5: Sufficient nutrients from tillering to early panicle initiation and flowering Part 1: Understanding the Palay. Check System

Nutrient facts § Nutrients are what plants need to grow and become productive. § Proper nutrient management improves crop growth and yield. § Rice plants grow and respond better to fertilizer when there is more sunlight. § Of all nutrient elements, rice plants need more of the following macronutrients: N, P, K, Zn, S

Why do rice plants need fertilizers? Climate Nutrient inputs as fertilizers fill the gap between crop need and indigenous supply. N-P-K Organic fert Crop residues Soil Irrigation water Indigenous nutrient supply Inorganic fertilizer

Sufficient nutrients from tillering to early panicle initiation (EPI) and flowering ensures good and uniform growth, panicle development, and attainment of yield potential more panicles, more grains increased yield from many tillers and panicles nutrients are needed to produce many tillers, panicles and filled for uniform grains maturity

Assessment of Key Check 5 Applied N fertilizer at tillering to EPI and flowering if leaf color chart (LCC) reading is below 4 for transplanted and below 3 for direct wet -seeded rice. urea WS = 1 bag/ha urea DS = 1. 5 bag/ha

Assessment of Key Check 5 For transplanted rice Achieved at least 300 panicles/m 2 at flowering stage. Randomly select 10 hills in a diagonal line across the field and count the panicles. Compute the number of panicles/m 2. Panicles/m 2 = Total number of panicles x Number of hills/m 2 10 hills

Assessment of Key Check 5 For direct wet-seeded rice Achieved at least 350 panicles/m 2 at flowering stage. Use a 0. 5 m x 0. 5 m quadrat (0. 25 m 2). Randomly select 3 sampling sites at least 1 m from the levee and in a diagonal line across the field. Count the panicles from each quadrat and get the average. Compute for the number of panicles/m 2. No. of panicles/m 2 = Ave. number of panicles 0. 25 m 2 hills

HOW TO ACHIEVE Key Check 5?

HOW TO ACHIEVE KEY CHECK 5? Know and manage the nutrient requirement of your crop based on the available information and nutrient assessment and decision-support tools. Leaf Color Chart Minus-One Element Technique Nutrient Omission Plot

Minus-One Element Technique A pot experiment to determine the nutrients deficient in the soil. Leaf Color Chart A tool to visually assess the nitrogen status of rice crops. Nutrient Omission Plot A means to assess indigenous nutrient supply to serve as basis of fertilizer recommendation.

New! Nutrient Manager for Rice a computer-based decision tool software providing field-specific nutrient management guidelines for rice

Consider this! Aside from nutrient deficiency, consider mineral toxicity in deciding on the nutrients to apply. Toxicity can occur when minerals exist in a form that becomes harmful to plants. Worms (parasites) live in every person’s intestines, no matter how clean and healthy a person is.

IRON TOXICITY Iron is naturally present in the soil and plants need iron. But iron can be harmful in permanently-flooded fields. tiny brown spots on the lower leaves starting from the tip or orange-yellow to brown leaves IRRI WHAT TO DO? Use intermittent irrigation and avoid continuous flooding in poorly-drained soils, balance fertilizers and perform dry tillage after harvest to increase iron oxidation during the fallow period.

HOW TO ACHIEVE KEY CHECK 5? Know and manage the nutrient requirement of your crop based on the available information, nutrient assessment and decision-support tools. Knowing right kind, amount, and timing of fertilizer application. The right KAT!

Right KAT! Right kind • giving the right nutrients increases cost efficiency and attainment of yield target Right amount • too much nutrients may increase pest damage • lack of nutrients may lead to slower growth of seedlings, fewer number of tillers, and lighter grain weight Right timing • wrong timing of fertilizer application increases input cost and decreases efficiency in nutrient uptake

NITROGEN Deficiency symptoms: Stunted, yellowish plants. Older leaves or whole plants are yellowish green.

Kind Nitrogen (N) promotes rapid growth for: • increased plant height and number of tillers • increased leaf size • spikelet number panicle • percentage filled spikelets in each panicle • grain protein content NITROGEN

Amount NITROGEN Too much N particularly between panicle initiation and flowering makes the plant prone to lodging and pests. Excessive N application is costly. Use results of LCC and Nutrient Manager as basis in properly determining the amount of N to apply.

Timing NITROGEN Use the LCC every 7 days from 14 DAT or 21 DAS until early flowering. If 14 -14 -14 -12 S is applied at 14 DAT or 21 DAS, LCC reading starts at 21 DAT or 28 DAS. Determine right time of N application by using LCC. If more than 5 out of 10 leaves are below 4, apply 1. 5 bags urea or 3. 5 bags 21 -0 -0 -24 S during WS. (Use ammonium sulfate instead of urea if plant shows sulfur deficiency or if sulfur-containing fertilizer is not used. )

Timing NITROGEN (Basal) Organic g in en rip g in er w flo e cl n ni tio pa itia in g rin le til g lin n io at ep pr in nd rm ed se ge la

PHOSPHORUS Deficiency symptoms: Stunted dark green plants with narrow, short, very erect leaves and greatly reduced tillering.

Kind Phosphorus (P) promotes tillering, root development, early flowering, and ripening. Lack in phosphorus causes thin stems and retarded development. The number of leaves, panicles, and grains per panicle are also reduced. PHOSPHORUS

Amount PHOSPHORUS Use results of MOET test and Nutrient Manager as basis in properly determining the amount of P to apply.

Timing PHOSPHORUS (Basal) Organic g in en rip g in er w flo e cl n ni tio pa itia in g rin le til g lin ed n io at ep pr in nd rm se ge la

POTASSIUM Deficiency symptoms: Dark green plants with yellowish brown leaf margins or dark brown necrotic spots first appear on the tip of older leaves.

Kind Potassium (K) improves root growth and plant vigor and helps prevent lodging. It also enhances crop resistance to pests and diseases. K deficiency is often not detected because its symptoms do not appear until the later growth stages and are not as easy to recognize as that of N deficiency. POTASSIUM

Amount POTASSIUM Use results of MOET test and Nutrient Manager as basis in properly determining the amount of K to apply.

Timing POTASSIUM (Basal) Organic fert g in en rip g in er w flo e cl n ni tio pa itia in g rin le til g lin ed n io at ep pr in nd rm se ge la

ZINC Deficiency symptoms: Dusty brown spots on upper leaves of stunted plants appearing 2 -4 weeks after transplanting

Kind ZINC Zinc (Zn) promotes good seedling and overall growth of plants. Zn deficiency problem must be corrected to attain high yields. In Zndeficient soils, NPK fertilizers alone cannot provide good yield unless Zn deficiency is corrected.

Amount Apply 25 kg zinc sulfate per ha at 14 DAT once a year during DS. Use results of MOET test and Nutrient Manager as basis in properly determining the amount of Zn to apply. ZINC

Timing ZINC 14 DAT Zn. SO 4 Organic g in en rip g in er w flo e cl n ni tio pa itia in g rin le til g lin ed n io at ep pr in nd rm se ge la

SULFUR Deficiency symptoms: yellowing of young leaves, reduced no. of tillers, fewer and shorter panicles, reduced no. of spikelets per panicle, and delayed maturity

Kind Sulfur (S) promotes uniform growth and maturity. SULFUR

Amount SULFUR The amount of sulfur in 14 -14 -14 -12 S (12% sulfur) as recommended to treat P and K deficiencies is adequate to correct usual sulfur deficiency. Use results of MOET test and Nutrient Manager as basis in properly determining the amount of S to apply.

Timing SULFUR Use 14 -14 -14 -12 S as basal or topdress 21 -0 -0 -25 S (ammonium sulfate) instead of urea. Use 3. 5 bags ammonium sulfate/ha in the dry season and 2 bags ammonium sulfate/ha in the wet season.

Timing SULFUR Organic g in en rip g in er w flo e cl n ni tio pa itia in g rin le til g lin ed n io at ep pr in nd rm se ge la

In summary… K Know the right KIND of nutrients your plant needs. Use nutrient assessment and decision-support tools to guide you in determining the right fertilizer to use. A Know the right AMOUNT of fertilizer to apply. Too much or too little is not good. T Know the right TIMING of fertilizer application to increase efficiency in input cost and nutrient uptake.

INPUTS • Right kind of fertilizer used • Right amount of fertilizer applied • Right timing of fertilizer application OUTPUTS • Sufficient nutrients during tillering to early panicle initiation and flowering OUTCOME • Good yield

Let’s review! Sulfur Zinc Nitrogen Phosphorus Potassium g in en rip g n tio tia i in in er w flo e cl ni pa g in r le til g lin ed se n io at in rm ge

Matching game N def Fe toxicity S def Zn def P def N def P def K def S def Zn def Fe toxicity

Nutrient Management Key Check 5: Sufficient nutrients from tillering to early panicle initiation and flowering

CREDITS Instructional presentation designer: Ms. Ev Parac Sources of technical content/reviewers of presentation: Mr. Wilfredo Collado; Mr. Efren Laureles, IRRI; Mrs. Constancia Mangao and Mrs. Pelagia Orpia, BSWM Note: Adapted from powerpoint presentations developed by: Ms. Evelyn F. Javier, Mr. Salvador Yabes; Engr. Eugenio Castro, IRRI; Dr. Manny Regalado You may use, remix, tweak, For more information, visit: & build upon this presentation non-commercially. However, always use with acknowledgment. Unless otherwise stated, the names listed are Phil. Rice staffers. Produced in 2011. Text: 0920 -911 -1398