A	Kriging	Approach	for	Representing	Crop	

Progress	and	Condition	at	Small	Domains

Arthur	Rosales	

USDA	|	NASS	

arthur.rosales@usda.gov	

2021	FCSM		|		Concurrent	Session	J-3	|	Nov	2-4,	2021 1	
Disclaimer	

The	Findings	and	Conclusions	in	This	Preliminary	

Presentation	Have	Not	Been	Formally	Disseminated	by	

the	U.	S.	Department	of	Agriculture	and	Should	Not	Be

Construed	to	Represent	Any	Agency	Determination	or	

Policy	
Outline 

• Overview	of	NASS	Crop	Progress	and	Condition	

• Description	of	issues	faced	by	users	

• Introduction	of	new	small	domain	product	

• Data	access	details	

2021	FCSM		|		Concurrent	Session	J-3	|	Nov	2-4,	2021 3	
NASS Crop Progress and Condition 

Survey 

• The	USDA	National	Agricultural	Statistics	Service	(NASS)	provides	

crop	progress	and	condition	estimates	for	selected	crops	on	a	

weekly	basis	during	crop	specific	growing	seasons	

• Crop	progress	and	condition	estimates	are	obtained	from	data	

provided	by	the	non-probability	crop	progress	and	condition	survey	

of	crop	experts	(not	farmers)	

• Approximately	3600	experts	participate	in	the	survey	annually,	

representing	the	3108	agricultural	counties	in	the	lower	48	United	

States	

2021	FCSM		|		Concurrent	Session	J-3	|	Nov	2-4,	2021 4	
NASS Crop Progress and Condition 

Survey 

• Based	on	standard	definitions,	the	expert	respondents	

subjectively	estimate:	

o Progress	of	crops	through	various	stages	of	observed	

development	as	well	as	by	producer	activities	

o Condition	of	crops	through	visual	evaluation	and	

interaction	with	crop	producers.	

• Weekly	reports	are	reviewed	for	reasonableness	and	

consistency,	and	data	is	aggregated	to	state	and	national	

levels	using	weights	derived	from	historical	NASS	acreage	

estimates	

2021	FCSM		|		Concurrent	Session	J-3	|	Nov	2-4,	2021 5	
Current Data Format 

Crop	Condition:	

• Condition	for	any	given	crop	is	reported	

as	a	breakdown	of:	

• Very	Poor	

• Poor	

• Fair	

• Good	

• Excellent	

• Condition	for	a	crop	is	expressed	in	

terms	of	percentages	within	each	

category,	always	adding	up	to	100%	

• Ranges	from	100%	very	poor	to	100%	

excellent	

Iowa	

2021	FCSM		|		Concurrent	Session	J-3	|	Nov	2-4,	2021 6	
Current Data Format 

Crop	Progress:	

• Progress	also	uses	a	percentage-in-category	system	like	crop	condition,	but	

the	categories	vary	by	crop.	The	corn	crop	within	a	county	can	be	some	

percent	of	each	category,	ranging	from	0%	planted	to	100%	harvested:	

Corn	Progress	Categories	

• Planted		

• Emerged	

• Silked	

• Doughed	

• Dented	

• Matured	

• Harvested	

Iowa	

2021	FCSM		|		Concurrent	Session	J-3	|	Nov	2-4,	2021 7	
Current Data Format: Issues 

Progress	and	Condition	is	aggregated	at	the	state	and	national	levels	for	public	

use.	This	is	done	to	protect	the	confidentiality	of	producers,	and	to	enhance	

stability	of	estimates.	However,	this	presents	issues	for	data	users:	

• State	summaries	do	not	represent	within-state	trends	and	variability	

• There	is	no	indication	which	counties	or	regions	within	the	state	actually	

contribute	to	reports	

2021	FCSM		|		Concurrent	Session	J-3	|	Nov	2-4,	2021 8	
Exaggerated Example 

One	estimate	for	the	state...	 ...from	sparse	and	geographically	biased	inputs	

2021	FCSM		|		Concurrent	Session	J-3	|	Nov	2-4,	2021 9	
The	new	Crop	Progress	and	Condition	Gridded	Layers	addresses	

these	issues	by	representing	trends	in	condition	and	progress	of	

major	commodity	crops	throughout	the	growing	season,	while	

obscuring	the	actual	county-level	data.	

This	is	achieved	in	two	main	steps:	

1. Represent	county	progress	and	condition	as	simplified	numeric	

indices	or	percentages	based	on	the	original	percent-in-category	

data.	

2. Interpolate	these	values	across	the	lower	48	states	as	a	

continuous	raster	surface,	independent	of	county	boundaries.		

New Product for Smaller Domains 

2021	FCSM		|		Concurrent	Session	J-3	|	Nov	2-4,	2021 10	
Step 1: 

Reduce Original Data Into Numeric 

Indices 

2021	FCSM		|		Concurrent	Session	J-3	|	Nov	2-4,	2021 11	
Condition Index 

• Crop	Condition	Index	combines	all	categorical	condition	percentages	into	

single	number:	

Corn	Condition	Index	=	

Corn	Condition	Index	=	(5*excellent	+	4*good	+	3*fair	+	2*poor	+	very	poor)/100	

• 	Values	range	from	1	to	5,	where	1	is	100%	“Very	Poor”,	and	5	is	100%	

“Excellent”	

2021	FCSM		|		Concurrent	Session	J-3	|	Nov	2-4,	2021 12	
Condition Index 

County	 Excellent	 Good	 Fair	 Poor	 Very	Poor	 Con.	Index	

05029	 100%	 0%	 0%	 0%	 0%	 5	

05031	 80%	 20%	 0%	 0%	 0%	 4.8	

05033	 25%	 20%	 50%	 5%	 0%	 3.65	

05035	 0%	 50%	 50%	 0%	 0%	 3.5	

05037	 20%	 20%	 30%	 20%	 10%	 3.2	

05039	 0%	 60%	 25%	 15%	 0%	 3.45	

05041	 20%	 75%	 5%	 0%	 0%	 4.15	

05043	 40%	 50%	 10%	 0%	 0%	 4.3	

05045	 10%	 40%	 50%	 0%	 0%	 3.6	

05047	 30%	 32%	 17%	 21%	 0%	 3.71	

05049	 28%	 41%	 20%	 10%	 1%	 3.85	

05051	 36%	 36%	 28%	 0%	 0%	 4.08	

05053	 36%	 36%	 28%	 0%	 0%	 4.08	

05055	 30%	 50%	 20%	 0%	 0%	 4.1	

05057	 10%	 10%	 40%	 30%	 10%	 2.8	

05059	 36%	 36%	 28%	 0%	 0%	 4.08	

05061	 10%	 10%	 40%	 30%	 10%	 2.8	

05063	 44%	 39%	 16%	 1%	 0%	 4.26	

05065	 28%	 41%	 20%	 10%	 1%	 3.85	

05067	 0%	 75%	 25%	 0%	 0%	 3.75	

05069	 10%	 50%	 30%	 10%	 0%	 3.6	

05071	 0%	 0%	 0%	 100%	 0%	 2	 2021	FCSM		|		Concurrent	Session	J-3	|	Nov	2-4,	2021 13	
Progress Index 

• Proposed	crop	progress	index	combines	all	categorical	progress	

percentages	into	a	single	number.	This	would	be	based	on	different	

categories	depending	on	the	crop.	

Winter	Wheat	Progress	Index	=	

Wheat	Progress	Index	=	(harvested	+	heading	+	emerging	+	planting)/400	

• Values	range	from	0	to	1,	where	0	represents	0%	planted	and	1	represents	

100%	harvested	

2021	FCSM		|		Concurrent	Session	J-3	|	Nov	2-4,	2021 14	
Progress Index 

15	

Counties	

Growing	Season	

2021	FCSM		|		Concurrent	Session	J-3	|	Nov	2-4,	2021
Crop	Condition	Index:	

County	Level	

Very	Poor	

Poor	

Fair	

Good	

Excellent	

2021	FCSM		|		Concurrent	Session	J-3	|	Nov	2-4,	2021 16	
Step 2: 

Interpolating County-Level Numeric Data 

17	

Corn	Progress,	Week	27,	2019	

2021	FCSM		|		Concurrent	Session	J-3	|	Nov	2-4,	2021
18	

Geostatistical Approach 

Input	Points	

2021	FCSM		|		Concurrent	Session	J-3	|	Nov	2-4,	2021 Output	Surface	
Kriging	Input	

• Need	a	set	of	input	points	to	run	

kriging	algorithm	

• Could	use	county	centroids,	but	

they	do	not	represent	crop	

acreage	or	location	across	the	US	

• Therefore,	an	input	point	schema	

representing	crop	acreage	was	

devised	

19	

Geostatistical Approach 

County	Centroids	

2021	FCSM		|		Concurrent	Session	J-3	|	Nov	2-4,	2021
Derive Crop Area/Location Based Sampled 

Points 

Determine	known	areas	from		

Cropland	Data	Layer	(CDL)	

Create	“zones”	of	crop	area	

within	counties,	based	on	CDL	

information	

Create	sample	of	random	lat/long	

points	within	each	county	zone,	

proportional	to	planted	acres	

Zone	creation	Illustration	

Density	and	location	of	

points	corresponds	with	

cropland	of	interest	

2021	FCSM		|		Concurrent	Session	J-3	|	Nov	2-4,	2021 20	
Kriging Input Point Schema 

• Using	this	point	dataset	as	input	for	kriging	

allows	us	to:	

o Weigh	the	county	contribution	by	planted	acres	

oUse	points	which	represent	the	probable	location	

of	planted	crops	

oPerform	univariate	kriging,	where	all	input	points	

are	based	on	the	original	reported	data	

Acreage/Location	Based	Points	

	Merged	with	County	Centers	

Univariate	Kriging	 2021	FCSM		|		Concurrent	Session	J-3	|	Nov	2-4,	2021 21	
Kriged Surface 

US	corn	progress,	week	27	of	2019

2021	FCSM		|		Concurrent	Session	J-3	|	Nov	2-4,	2021 22	
Resolution of New Data 

23	

US	corn	condition,	week	34	of	2020

2021	FCSM		|		Concurrent	Session	J-3	|	Nov	2-4,	2021
Data Availability 

• Raster	datasets	representing	both	progress	and	condition	for	each:	

• Corn	

• Soy	

• Winter	Wheat	

• Cotton	(2022)	

• Data	format	is	9km	raster	geoTIFF	files	covering	the	contiguous	

United	States	

• Each	new	dataset	is	released	within	a	day	of	NASS	progress	and	

condition	data	becoming	available	

• Data	archive	to	be	created	for	Crop	Progress	and	Condition	data,	

2015-Present	

2021	FCSM		|		Concurrent	Session	J-3	|	Nov	2-4,	2021 24	
Data Availability 

https://www.nass.usda.gov/Research_and_Science/Crop_Progress_Gridded_Layers/index.php

2021	FCSM		|		Concurrent	Session	J-3	|	Nov	2-4,	2021 25	
Thank	You	

Arthur	Rosales	

arthur.rosales@usda.gov	

https://www.nass.usda.gov/Research_and_Science/Crop_Progress_Gridded_Layers/index.php

2021	FCSM		|		Concurrent	Session	J-3	|	Nov	2-4,	2021 26